diff -ur phase3/includes/DefaultSettings.php blahtex/includes/DefaultSettings.php
--- phase3/includes/DefaultSettings.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/DefaultSettings.php	2006-05-20 01:26:33.000000000 +1000
@@ -1097,6 +1097,10 @@
 $wgUseTeX = false;
 /** Location of the texvc binary */
 $wgTexvc = './math/texvc';
+/** Location of the blahtex binary. If empty, texvc is used instead */
+$wgBlahtex = '';
+/** Command-line options for blahtex */
+$wgBlahtexOptions = '--texvc-compatible-commands --mathml-version-1-fonts --disallow-plane-1 --spacing strict';
 
 #
 # Profiling / debugging
diff -ur phase3/includes/Math.php blahtex/includes/Math.php
--- phase3/includes/Math.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/Math.php	2006-05-20 01:44:56.000000000 +1000
@@ -1,198 +1,580 @@
 <?php
 /**
- * Contain everything related to <math> </math> parsing
- * @package MediaWiki
+ * @file Math.php
+ * Contains everything related to <math> </math> parsing.
+ * \sa math/README
  */
 
 /**
- * Takes LaTeX fragments, sends them to a helper program (texvc) for rendering
- * to rasterized PNG and HTML and MathML approximations. An appropriate
- * rendering form is picked and returned.
- *
- * by Tomasz Wegrzanowski, with additions by Brion Vibber (2003, 2004)
+ * %Parser for the blahtex's output. 
+ */
+class blahtexOutputParser  {
+   var $parser;  /**< \private */
+	var $stack;   /**< \private */
+	var $results; /**< \private */
+
+	function blahtexOutputParser()
+	{
+		$this->parser = xml_parser_create( "UTF-8" );
+		$this->stack = array();
+		$this->results = array();
+		$this->prevCdata = false;
+		
+		xml_set_object( $this->parser, $this );
+		xml_parser_set_option( $this->parser, XML_OPTION_CASE_FOLDING, 0 );
+		xml_set_element_handler( $this->parser, "startElement", "stopElement" );
+		xml_set_character_data_handler( $this->parser, "characterData" );
+	}
+
+	/**
+	 * Main function, which parses blahtex's output.
+	 * The format of blahtex's output is based on XML. This function
+	 * parses the XML and returns an array representing the tree
+	 * structure. For instance, if $retval denotes the return value,
+	 * then $retval["blahtex"]["error"] contains the text within the
+	 * <error> tag within the <blahtex> tag. If there is more than one
+	 * <error> tag within a <blahtex> tag, then
+	 * $retval["blahtex"]["error"] is an array of strings. As a special
+	 * case, $retval["mathmlMarkup"] contains the segment between
+	 * <markup> and </markup>.
+	 * @param $data String with output to be parsed.
+	 * @return Array representing XML tree.
+	 */
+	function parse( $data )
+	{
+		// We splice out any segment between <markup> and </markup>  
+		// so that the XML parser doesn't have to deal with all the MathML tags.
+		$markupBegin = strpos( $data, "<markup>" );
+		if ( !( $markupBegin === false ) ) {
+			$markupEnd = strpos( $data, "</markup>" );
+			$this->results["mathmlMarkup"] = 
+				trim( substr( $data, $markupBegin + 8, $markupEnd - $markupBegin - 8 ) );
+			$data = substr( $data, 0, $markupBegin + 8 ) . substr( $data, $markupEnd );
+		}
+		xml_parse( $this->parser, $data );
+		return $this->results;
+	}
+
+	/** @privatesection */
+	function startElement( $parser, $name, $attributes )
+	{
+		$this->prevCdata = false;
+		if ( count( $this->stack ) == 0 )
+			array_push( $this->stack, $name );
+		else
+			array_push( $this->stack, $this->stack[count( $this->stack ) - 1] . ":$name" );
+	}
+	
+	function stopElement($parser, $name)
+	{
+		$this->prevCdata = false;
+		array_pop( $this->stack );
+	}
+	
+	function characterData($parser, $data)
+	{
+		$index = $this->stack[count( $this->stack ) - 1];
+		if ( $this->prevCdata ) {
+			// Merge subsequent CDATA blocks
+			if ( is_array( $this->results[$index] ) )
+				array_push( $this->results[$index], 
+					    array_pop( $this->results[$index] ) . $data);
+			else
+				$this->results[$index] .= $data;
+		} else {
+			if ( !isset( $this->results[$index] ) ) 
+				$this->results[$index] = $data;
+			elseif ( is_array( $this->results[$index] ) )
+				array_push( $this->results[$index], $data );
+			else
+				$this->results[$index] = array( $this->results[$index], $data );
+		}
+		$this->prevCdata = true;
+	}
+}
+
+/**
+ * Render formulas to PNG, HTML and MathML.
+ * Takes LaTeX fragments, sends them to helper program (texvc and
+ * blahtex) for rendering to rasterized PNG and HTML and MathML
+ * approximations. An appropriate rendering form is picked, depending
+ * on the user's preferences, and returned. The rendering is cached in
+ * the @c math table in the database, and the PNG files are cached in
+ * @c $wgMathDirectory on the file system.
  *
- * @package MediaWiki
+ * @author Tomasz Wegrzanowski, with additions by Brion Vibber (2003, 2004)
  */
 class MathRenderer {
-	var $mode = MW_MATH_MODERN;
-	var $tex = '';
-	var $inputhash = '';
-	var $hash = '';
-	var $html = '';
-	var $mathml = '';
-	var $conservativeness = 0;
-
+	/** @privatesection */
+   var $mode = MW_MATH_MODERN; /**< @User preference for maths */
+	var $tex = '';              /**< LaTeX fragment */
+	var $inputhash = '';        /**< Hash value of $tex */
+	var $hash = '';             /**< Name of PNG file */
+	var $html = '';             /**< HTML rendering of $tex */
+	var $mathml = '';           /**< MathML rendering of $tex */
+	var $conservativeness = 0;  /**< How conservative the HTML rendering is */
+	
+	/**
+	 * Constructor.
+	 * @param $tex String containing LaTeX fragment to be rendered.
+	 * @public 
+	 */
 	function MathRenderer( $tex ) {
 		$this->tex = $tex;
- 	}
-
+	 }
+	
+	/**
+	 * Set the preferred output mode.
+	 * The output mode specifies whether render() should output PNG,
+	 * HTML or MathML.
+	 * @param $mode Output mode, can be @c MW_MATH_PNG, 
+	 *    @c MW_MATH_SIMPLE, @c MW_MATH_HTML, @c MW_MATH_SOURCE,
+	 *    @c MW_MATH_MODERN, or @c MW_MATH_MATHML.
+	 * @public
+	 */
 	function setOutputMode( $mode ) {
 		$this->mode = $mode;
 	}
 
+	/**
+	 * Main function, which renders the LaTeX fragment.
+	 * This function renders the LaTeX fragment specified in the
+	 * constructor. The output depends on the output mode, set with
+	 * setOutputMode(), as follows:
+	 *  - @c MW_MATH_PNG : Output is in PNG format, fall back to HTML.
+	 *  - @c MW_MATH_SIMPLE : Output is in HTML format if the HTML is
+	 *       simple and in PNG otherwise.
+	 *  - @c MW_MATH_HTML : Output is in HTML format, fall back to PNG.
+	 *  - @c MW_MATH_SOURCE : Output the LaTeX fragment verbatim,
+	 *       surrounded by a pair of @c $ characters.
+	 *  - @c MW_MATH_MODERN : Output is in HTML format unless the HTML
+	 *       is complicated, fall back to PNG.
+	 *  - @c MW_MATH_MATHML : Output is in MathML format, fall back to
+	 *       PNG.
+	 *
+    * @return String containing HTML fragment, representing the
+    * formula in the given LaTeX fragment.
+	 * @public
+	 */
 	function render() {
-		global $wgTmpDirectory, $wgInputEncoding;
-		global $wgTexvc;
+		global $wgBlahtex;
 		$fname = 'MathRenderer::render';
-
+	
 		if( $this->mode == MW_MATH_SOURCE ) {
 			# No need to render or parse anything more!
-			return ('$ '.htmlspecialchars( $this->tex ).' $');
+			return ( '$ '.htmlspecialchars( $this->tex ).' $' );
 		}
-
+		
 		if( !$this->_recall() ) {
-			# Ensure that the temp and output directories are available before continuing...
-			if( !file_exists( $wgTmpDirectory ) ) {
-				if( !@mkdir( $wgTmpDirectory ) ) {
-					return $this->_error( 'math_bad_tmpdir' );
-				}
-			} elseif( !is_dir( $wgTmpDirectory ) || !is_writable( $wgTmpDirectory ) ) {
-				return $this->_error( 'math_bad_tmpdir' );
+			$res = $this->testEnvironment();
+			if ( $res )
+				return $res;
+			
+			// Run texvc
+			list( $success, $res ) = $this->invokeTexvc( $this->tex );
+			if ( !$success )
+				return $res;
+			$texvcError = $this->processTexvcOutput( $res );
+			
+			// Run blahtex, if configured
+			if ( $wgBlahtex ) {
+				list( $success, $res ) = $this->invokeBlahtex( $this->tex, $this->hash == NULL );
+				if ( !$success )
+					return $res;
+				$parser = new blahtexOutputParser();
+				$res = $parser->parse( $res );
+				wfDebug(print_r($res, TRUE));
+				$blahtexError = $this->processBlahtexOutput( $res );
+				if ( $blahtexError && $texvcError )
+					return $blahtexError;
+			} else {
+				if ( $texvcError )
+					return $texvcError;
 			}
 
-			if( function_exists( 'is_executable' ) && !is_executable( $wgTexvc ) ) {
-				return $this->_error( 'math_notexvc' );
-			}
-			$cmd = $wgTexvc . ' ' .
-					escapeshellarg( $wgTmpDirectory ).' '.
-					escapeshellarg( $wgTmpDirectory ).' '.
-					escapeshellarg( $this->tex ).' '.
-					escapeshellarg( $wgInputEncoding );
-
-			if ( wfIsWindows() ) {
-				# Invoke it within cygwin sh, because texvc expects sh features in its default shell
-				$cmd = 'sh -c ' . wfEscapeShellArg( $cmd );
+			# Now save it back to the DB:
+			if ( !wfReadOnly() ) {
+				if ( $this->hash )
+					$outmd5_sql = pack( 'H32', $this->hash );
+				else
+					$outmd5_sql = '';
+			
+				$md5_sql = pack( 'H32', $this->md5 ); # Binary packed, not hex
+				
+				$dbw =& wfGetDB( DB_MASTER );
+				$dbw->replace( 'math', array( 'math_inputhash' ),
+				  array( 
+					'math_inputhash' => $md5_sql, 
+					'math_outputhash' => $outmd5_sql,
+					'math_html_conservativeness' => $this->conservativeness,
+					'math_html' => $this->html,
+					'math_mathml' => $this->mathml,
+				  ), $fname, array( 'IGNORE' ) 
+				);
 			}
+		}
+		  
+		return $this->_doRender();
+	}
 
-			wfDebug( "TeX: $cmd\n" );
-			$contents = `$cmd`;
-			wfDebug( "TeX output:\n $contents\n---\n" );
-
-			if (strlen($contents) == 0) {
-				return $this->_error( 'math_unknown_error' );
+	/**
+	 * Test whether the necessary directories and executables exist.
+	 * @return String containing HTML fragment with error message if
+	 * there is a problem, @c false otherwise.
+	 */
+	function testEnvironment()
+	{
+		global $wgTmpDirectory, $wgTexvc, $wgBlahtex;
+		
+		if( !file_exists( $wgTmpDirectory ) ) {
+			if( !@mkdir( $wgTmpDirectory ) ) {
+				return $this->_error( 'math_bad_tmpdir' );
 			}
+		} elseif( !is_dir( $wgTmpDirectory ) || !is_writable( $wgTmpDirectory ) ) {
+			return $this->_error( 'math_bad_tmpdir' );
+		}
+		
+		if( function_exists( 'is_executable' ) && !is_executable( $wgTexvc ) ) {
+			return $this->_error( 'math_notexvc' );
+		}
+		if ($wgBlahtex && function_exists( 'is_executable' ) && !is_executable( $wgBlahtex ))
+			return $this->_error( 'math_noblahtex', $wgBlahtex );
+		
+		return false;
+	}
 
-			$retval = substr ($contents, 0, 1);
-			if (($retval == 'C') || ($retval == 'M') || ($retval == 'L')) {
-				if ($retval == 'C')
-					$this->conservativeness = 2;
-				else if ($retval == 'M')
-					$this->conservativeness = 1;
-				else
-					$this->conservativeness = 0;
-				$outdata = substr ($contents, 33);
+	/**
+	 * Invoke the texvc executable.
+	 * This function invokes the @c texvc helper program, whose
+	 * location is specified in $wgTexvc. 
+	 * @param $tex String containing the LaTeX fragment to be rendered.
+	 * @return A 2-tuple. 
+	 *  - If an error occurred, then the first element is @c false and
+	 *    the second element is a string containing an HTML fragment
+	 *    with the error message.
+	 *  - Otherwise, the first element is @c true and the second
+	 *    element s a string containing the output of @c texvc.
+	 */
+	function invokeTexvc( $tex )
+	{
+		global $wgMathDirectory, $wgTmpDirectory, $wgTexvc, $wgInputEncoding;
+
+		$cmd = $wgTexvc . ' ' . 
+			escapeshellarg( $wgTmpDirectory ).' '.
+			escapeshellarg( $wgTmpDirectory ).' '.
+			escapeshellarg( $this->tex ).' '.
+			escapeshellarg( $wgInputEncoding );
+					
+		if ( wfIsWindows() ) {
+			// Invoke it within cygwin sh, because texvc expects sh features in its default shell
+			$cmd = 'sh -c ' . wfEscapeShellArg( $cmd );
+		} 
+		
+		wfDebug( "TeX: $cmd\n" );
+		$contents = `$cmd`;
+		wfDebug( "TeX output:\n $contents\n---\n" );
+		
+		if ( strlen( $contents ) == 0 ) {
+			return array( false, $this->_error( 'math_unknown_error' ) );
+		}
 
-				$i = strpos($outdata, "\000");
+		return array( true, $contents );
+	}
 
-				$this->html = substr($outdata, 0, $i);
-				$this->mathml = substr($outdata, $i+1);
-			} else if (($retval == 'c') || ($retval == 'm') || ($retval == 'l'))  {
-				$this->html = substr ($contents, 33);
-				if ($retval == 'c')
-					$this->conservativeness = 2;
-				else if ($retval == 'm')
-					$this->conservativeness = 1;
-				else
-					$this->conservativeness = 0;
-				$this->mathml = NULL;
-			} else if ($retval == 'X') {
-				$this->html = NULL;
-				$this->mathml = substr ($contents, 33);
+	/**
+	 * Process texvc output.
+	 * Parse the output, fill the mathml, html, hash, and
+	 * conservativeness fields in the database and move the PNG image
+	 * to its final destination. 
+	 * @param $contents String containing texvc output.
+	 * @return String containing HTML fragment with error message if
+	 * an error occurred, @c false otherwise.
+	 */
+	function processTexvcOutput( $contents ) {
+		global $wgTmpDirectory;
+
+		$retval = substr( $contents, 0, 1 );
+		if ( ( $retval == 'C' ) || ( $retval == 'M' ) || ( $retval == 'L' ) ) {
+			if ( $retval == 'C' )
+				$this->conservativeness = 2;
+			else if ( $retval == 'M' )
+				$this->conservativeness = 1;
+			else
 				$this->conservativeness = 0;
-			} else if ($retval == '+') {
-				$this->html = NULL;
-				$this->mathml = NULL;
+			$outdata = substr( $contents, 33 );
+			
+			$i = strpos( $outdata, "\000" );
+			
+			$this->html = substr( $outdata, 0, $i );
+			$this->mathml = substr( $outdata, $i+1 );
+		} else if ( ( $retval == 'c' ) || ( $retval == 'm' ) || ( $retval == 'l' ) )  {
+			$this->html = substr( $contents, 33 );
+			if ( $retval == 'c' )
+				$this->conservativeness = 2;
+			else if ( $retval == 'm' )
+				$this->conservativeness = 1;
+			else
 				$this->conservativeness = 0;
-			} else {
-				$errbit = htmlspecialchars( substr($contents, 1) );
-				switch( $retval ) {
-					case 'E': return $this->_error( 'math_lexing_error', $errbit );
-					case 'S': return $this->_error( 'math_syntax_error', $errbit );
-					case 'F': return $this->_error( 'math_unknown_function', $errbit );
-					default:  return $this->_error( 'math_unknown_error', $errbit );
-				}
+			$this->mathml = NULL;
+		} else if ( $retval == 'X' ) {
+			$this->html = NULL;
+			$this->mathml = substr( $contents, 33 );
+			$this->conservativeness = 0;
+		} else if ( $retval == '+' ) {
+			$this->html = NULL;
+			$this->mathml = NULL;
+			$this->conservativeness = 0;
+		} else {
+			$errbit = htmlspecialchars( substr( $contents, 1 ) );
+			switch( $retval ) {
+			case 'E': return $this->_error( 'math_lexing_error', $errbit );
+			case 'S': return $this->_error( 'math_syntax_error', $errbit );
+			case 'F': return $this->_error( 'math_unknown_function', $errbit );
+			default:  return $this->_error( 'math_unknown_error', $errbit );
 			}
+		}
 
-			$this->hash = substr ($contents, 1, 32);
-			if (!preg_match("/^[a-f0-9]{32}$/", $this->hash)) {
-				return $this->_error( 'math_unknown_error' );
-			}
+		$this->hash = NULL;
+		$hash = substr( $contents, 1, 32 );
+		if ( !preg_match( "/^[a-f0-9]{32}$/", $hash ) ) {
+			return $this->_error( 'math_unknown_error' );
+		}
+		
+		if( !file_exists( "$wgTmpDirectory/{$hash}.png" ) ) {
+			return $this->_error( 'math_image_error' );
+		}
+		
+		$this->hash = $hash;
+		$tmp = $this->moveToMathDir( "{$hash}.png" );
+		if ( $tmp !== false ) {
+			$this->hash = NULL;
+			return $tmp;
+		}
 
-			if( !file_exists( "$wgTmpDirectory/{$this->hash}.png" ) ) {
-				return $this->_error( 'math_image_error' );
-			}
+		return false;
+	}
 
-			$hashpath = $this->_getHashPath();
-			if( !file_exists( $hashpath ) ) {
-				if( !@wfMkdirParents( $hashpath, 0755 ) ) {
-					return $this->_error( 'math_bad_output' );
-				}
-			} elseif( !is_dir( $hashpath ) || !is_writable( $hashpath ) ) {
-				return $this->_error( 'math_bad_output' );
-			}
+	/**
+	 * Invoke the blahtex executable.
+	 * This function invokes the @c blahtex helper program. The
+	 * location of the program is specified in $wgBlahtex. Extra
+	 * options may be specified in $wgBlahtexOptions.
+	 * @param $tex String containing the LaTeX fragment to be rendered.
+	 * @param $makePNG Boolean specifying whether blahtex should
+	 * generate both MathML and PNG (@c true) or only MathML (@c false).
+	 * @return A 2-tuple. 
+	 *  - If an error occurred, then the first element is @c false and
+	 *    the second element is a string containing an HTML fragment
+	 *    with the error message.
+	 *  - Otherwise, the first element is @c true and the second
+	 *    element s a string containing the output of @c blahtex.
+	 */
+	function invokeBlahtex( $tex, $makePNG )
+	{
+		global $wgBlahtex, $wgBlahtexOptions, $wgTmpDirectory;
+
+		$descriptorspec = array( 0 => array( "pipe", "r" ),
+					 1 => array( "pipe", "w" ) );
+		$options = '--mathml ' . $wgBlahtexOptions;
+		if ( $makePNG ) 
+			$options .= " --png --temp-directory $wgTmpDirectory --png-directory $wgTmpDirectory";
+
+		$process = proc_open( $wgBlahtex.' '.$options, $descriptorspec, $pipes );
+		if ( !$process ) {
+			return array( false, $this->_error( 'math_unknown_error', ' #1' ) );
+		}
+		fwrite( $pipes[0], '\\displaystyle ' );
+		fwrite( $pipes[0], $tex );
+		fclose( $pipes[0] );
+		
+		$contents = '';
+		while ( !feof($pipes[1] ) ) {
+			$contents .= fgets( $pipes[1], 4096 );
+		}
+		fclose( $pipes[1] );
+		if ( proc_close( $process ) != 0 ) {
+			// exit code of blahtex is not zero; this shouldn't happen
+			return array( false, $this->_error( 'math_unknown_error', ' #2' ) );
+		}
+		
+		return array( true, $contents );
+	}
 
-			if( !rename( "$wgTmpDirectory/{$this->hash}.png", "$hashpath/{$this->hash}.png" ) ) {
-				return $this->_error( 'math_output_error' );
+	/**
+	 * Process blahtex output.
+	 * Parse the output and fill the mathml field in the database. If
+	 * blahtex has also generated a PNG image, then update the hash
+	 * field as well move the PNG image to its final destination. 
+	 * @param $contents String containing blahtex output.
+	 * @return String containing HTML fragment with error message if
+	 * an error occurred, @c false otherwise.
+	 */
+	function processBlahtexOutput( $results )
+	{
+		if ( isset( $results["blahtex:logicError"] ) ) {
+			// Something went completely wrong
+			return $this->_error('math_unknown_error', $results["blahtex:logicError"]);
+
+		} elseif ( isset( $results["blahtex:error:id"] ) ) {
+			// There was a syntax error in the input
+			return $this->blahtexError( $results, "blahtex:error" );
+
+		} elseif (isset($results["mathmlMarkup"]) || isset($results["blahtex:png:md5"])) {
+			// We got some results
+			if ( isset( $results["mathmlMarkup"] ) )	 
+				$this->mathml = $results['mathmlMarkup'];
+			if ( isset( $results["blahtex:png:md5"] ) ) {
+				$this->hash = $results["blahtex:png:md5"];
+				$tmp = $this->moveToMathDir( "{$this->hash}.png" );
+				if ( $tmp !== false ) 
+					return $tmp;
 			}
+			return false;
 
-			# Now save it back to the DB:
-			if ( !wfReadOnly() ) {
-				$outmd5_sql = pack('H32', $this->hash);
-
-				$md5_sql = pack('H32', $this->md5); # Binary packed, not hex
+		} else {
+			// There is an error somewhere
+			if ( isset( $results["blahtex:mathml:error:id"] ) ) 
+				return $this->blahtexError( $results, "blahtex:mathml:error" );
+			if ( isset( $results["blahtex:png:error:id"] ) )
+				return $this->blahtexError( $results, "blahtex:png:error" );
+			return $this->_error( 'math_unknown_error', ' #3' );
+		}
+	}
 
-				$dbw =& wfGetDB( DB_MASTER );
-				$dbw->replace( 'math', array( 'math_inputhash' ),
-				  array(
-					'math_inputhash' => $md5_sql,
-					'math_outputhash' => $outmd5_sql,
-					'math_html_conservativeness' => $this->conservativeness,
-					'math_html' => $this->html,
-					'math_mathml' => $this->mathml,
-				  ), $fname, array( 'IGNORE' )
-				);
+	/**
+	 * Build an error message for blahtex.
+	 * @param $results Parse tree as returned by
+	 * blahtexOutputParser::parse() .
+	 * @param $node String representing the node in the tree that the
+	 * message is stored under.
+	 * @returns String containing HTML fragment with the error
+	 * message. 
+	 */
+	function blahtexError( $results, $node ) {
+		$id = 'math_' . $results[$node . ":id"];
+		$fallback = $results[$node . ":message"];
+		if ( isset( $results[$node . ":arg"] ) ) {
+			if ( is_array( $results[$node . ":arg"] ) ) {
+				// Error message has two or three arguments
+				$arg1 = $results[$node . ":arg"][0];
+				$arg2 = $results[$node . ":arg"][1];
+				if ( count( $results[$node . ":arg"][1] > 2 ) )
+					$arg3 = $results[$node . ":arg"][1];
+				else
+					$arg3 = '';
+				return $this->_error( $id, $arg1, $arg2, $arg3, $fallback );
+			} else {
+				// Error message has one argument
+				$arg = $results[$node . ":arg"];
+				return $this->_error( $id, $arg, '', '', $fallback );
 			}
-
 		}
+		else {
+			// Error message without arguments
+			return $this->_error( $id, '', '', '', $fallback );
+		}
+	}
+		
+	/**
+	 * Move a PNG image to its final destination.
+	 * The file is moved from $wgTmpDirectory to a directory under
+	 * $wgMathDirectory. This function assumes that $hash is set.
+	 * @param $fname String containing name of file to be moved.
+	 * @return String containing HTML fragment with error message if
+	 * an error occurred, @c false otherwise.
+	 */
+	function moveToMathDir( $fname ) {
+		global $wgTmpDirectory;
 
-		return $this->_doRender();
+		$hashpath = $this->_getHashPath();
+		if( !file_exists( $hashpath ) ) {
+			if( !@wfMkdirParents( $hashpath, 0755 ) ) {
+				return $this->_error( 'math_bad_output' );
+			}
+		} elseif( !is_dir( $hashpath ) || !is_writable( $hashpath ) ) {
+			return $this->_error( 'math_bad_output' );
+		}
+		
+		if( !rename( "$wgTmpDirectory/$fname", "$hashpath/$fname" ) ) {
+			return $this->_error( 'math_output_error' );
+		}
+		return false;
 	}
 
-	function _error( $msg, $append = '' ) {
-		$mf   = htmlspecialchars( wfMsg( 'math_failure' ) );
-		$errmsg = htmlspecialchars( wfMsg( $msg ) );
+	/**
+	 * Build an error message in HTML.
+	 * @param $msg String containing lookup key for the message; will
+	 * be passed on to wfMsg() .
+	 * @param $arg1 String containing first argument for the message.
+	 * @param $arg2 String containing second argument for the message.
+	 * @param $arg3 String containing third argument for the message.
+	 * @param $fallback String containing a fallback message in case
+	 * the lookup key in $msg is not found.
+	 * @return String containing HTML fragment with the error message.
+	 */
+	function _error( $msg, $arg1 = '', $arg2 = '', $arg3 = '', $fallback = NULL ) {
+		$mf = htmlspecialchars( wfMsg( 'math_failure' ) );
+		if ( $msg ) {
+			if ( $fallback && wfMsg( $msg ) == '&lt;' . htmlspecialchars( $msg ) . '&gt;' ) 
+				$errmsg = htmlspecialchars( $fallback );
+			else
+				$errmsg = htmlspecialchars( wfMsg( $msg, $arg1, $arg2, $arg3 ) );
+		}
+		else
+			$errmsg = '';
 		$source = htmlspecialchars( str_replace( "\n", ' ', $this->tex ) );
-		return "<strong class='error'>$mf ($errmsg$append): $source</strong>\n";
+		// Note: the str_replace above is because the return value must not contain newlines
+		return "<strong class='error'>$mf ($errmsg): $source</strong>\n";
 	}
 
+	/**
+	 * Recall cached information from the database.
+	 * This function computes the hash value for the formula specified
+	 * in $tex and looks whether any information is stored in the @c
+	 * math table in the database. In that case, the $hash,
+	 * $conservativeness, $html and $mathml member variables are
+	 * updated. 
+	 * @return @c true if information was found in the database, @c
+	 * false if not.
+	 */
 	function _recall() {
 		global $wgMathDirectory;
 		$fname = 'MathRenderer::_recall';
 
 		$this->md5 = md5( $this->tex );
 		$dbr =& wfGetDB( DB_SLAVE );
-		$rpage = $dbr->selectRow( 'math',
-			array( 'math_outputhash','math_html_conservativeness','math_html','math_mathml' ),
-			array( 'math_inputhash' => pack("H32", $this->md5)), # Binary packed, not hex
-			$fname
+		$rpage = $dbr->selectRow( 'math', 
+					  array( 'math_outputhash','math_html_conservativeness','math_html','math_mathml' ),
+					  array( 'math_inputhash' => pack("H32", $this->md5)), # Binary packed, not hex
+					  $fname
 		);
 
-		if( $rpage !== false ) {
-			# Tailing 0x20s can get dropped by the database, add it back on if necessary:
+		if( $rpage === false ) 
+			return false; // Missing from the database
+
+		if( $rpage->math_outputhash == '' )
+			$this->hash = NULL;
+		else {
+			// Tailing 0x20s can get dropped by the database, add them back on if necessary:
 			$xhash = unpack( 'H32md5', $rpage->math_outputhash . "                " );
 			$this->hash = $xhash ['md5'];
+		}
+		
+		$this->conservativeness = $rpage->math_html_conservativeness;
+		$this->html = $rpage->math_html;
+		$this->mathml = $rpage->math_mathml;
+		
+		if( !$this->html && !$this->mathml && !$this->hash )
+			return false; // Database contains no useful information
 
-			$this->conservativeness = $rpage->math_html_conservativeness;
-			$this->html = $rpage->math_html;
-			$this->mathml = $rpage->math_mathml;
-
-			if( file_exists( $this->_getHashPath() . "/{$this->hash}.png" ) ) {
-				return true;
-			}
-
-			if( file_exists( $wgMathDirectory . "/{$this->hash}.png" ) ) {
-				$hashpath = $this->_getHashPath();
+		if( $this->hash) {
+			$hashpath = $this->_getHashPath();
 
+			// MediaWiki 1.5 / 1.6 transition:
+			// All files used to be stored directly under $wgMathDirectory
+			// Move them to the new layout if necessary
+			if( file_exists( $wgMathDirectory . "/{$this->hash}.png" )
+			    && !file_exists( $hashpath . "/{$this->hash}.png" ) ) {
 				if( !file_exists( $hashpath ) ) {
 					if( !@wfMkdirParents( $hashpath, 0755 ) ) {
 						return false;
@@ -202,35 +584,94 @@
 				}
 				if ( function_exists( "link" ) ) {
 					return link ( $wgMathDirectory . "/{$this->hash}.png",
-							$hashpath . "/{$this->hash}.png" );
+						      $hashpath . "/{$this->hash}.png" );
 				} else {
 					return rename ( $wgMathDirectory . "/{$this->hash}.png",
 							$hashpath . "/{$this->hash}.png" );
 				}
 			}
-
+			
+			if ( !file_exists( $hashpath . "/{$this->hash}.png" ) ) {
+				$this->hash = NULL; // File disappeared from the render cache
+				return false;
+			}
 		}
-
-		# Missing from the database and/or the render cache
-		return false;
+		
+		return true;
 	}
 
 	/**
-	 * Select among PNG, HTML, or MathML output depending on
+	 * Do the actual rendering.
+	 * After all preliminaries are completed, this function chooses
+	 * between PNG, HTML, or MathML output depending on the output mode
+	 * stored in $mode and the available options and returns a
+	 * rendering of the specified formula.
+	 * @return String containing HTML fragment representing the formula.
 	 */
 	function _doRender() {
-		if( $this->mode == MW_MATH_MATHML && $this->mathml != '' ) {
-			return "<math xmlns='http://www.w3.org/1998/Math/MathML'>{$this->mathml}</math>";
+
+		switch( $this->mode ) {
+
+		case MW_MATH_PNG: 
+			if( $this->hash )
+				$choice = 'png';
+			elseif ( $this->html )
+				$choice = 'html';
+			else
+				$choice = 'mathml';
+			break;
+
+		case MW_MATH_SIMPLE:
+			if( $this->hash && ( !$this->html || $this->conservativeness != 2 ) )
+				$choice = 'png';
+			elseif ( $this->html )
+				$choice = 'html';
+			else
+				$choice = 'mathml';
+			break;
+
+		case MW_MATH_HTML:
+			if ( $this->html )
+				$choice = 'html';
+			elseif( $this->hash )
+				$choice = 'png';
+			else
+				$choice = 'mathml';
+			break;
+
+		case MW_MATH_MODERN:
+			if( $this->hash && ( !$this->html || $this->conservativeness == 0 ) )
+				$choice = 'png';
+			elseif ( $this->html )
+				$choice = 'html';
+			else
+				$choice = 'mathml';
+			break;
+
+		case MW_MATH_MATHML:
+			if ( $this->mathml )
+				$choice = 'mathml';
+			elseif( $this->hash )
+				$choice = 'png';
+			else
+				$choice = 'html';
+			break;
+
 		}
-		if (($this->mode == MW_MATH_PNG) || ($this->html == '') ||
-		   (($this->mode == MW_MATH_SIMPLE) && ($this->conservativeness != 2)) ||
-		   (($this->mode == MW_MATH_MODERN || $this->mode == MW_MATH_MATHML) && ($this->conservativeness == 0))) {
+
+		if( $choice == 'mathml' )
+			return "<math xmlns='http://www.w3.org/1998/Math/MathML'>{$this->mathml}</math>";
+		elseif( $choice == 'png' )
 			return $this->_linkToMathImage();
-		} else {
+		else
 			return '<span class="texhtml">'.$this->html.'</span>';
-		}
 	}
 
+	/**
+	 * Construct a link to PNG file 
+	 * @return String containing HTML fragment with the PNG file
+	 * representing the formula. 
+	 */
 	function _linkToMathImage() {
 		global $wgMathPath;
 		$url = htmlspecialchars( "$wgMathPath/" . substr($this->hash, 0, 1)
@@ -240,6 +681,13 @@
 		return "<img class='tex' src=\"$url\" alt=\"$alt\" />";
 	}
 
+	/**
+	 * Get directory to store PNG image in.
+	 * The PNG images are stored in a tiered directory tree under
+	 * $wgMathDirectory. This function compute the directory that the
+	 * PNG image for the specified formula should go in.
+	 * @return String with directory path.
+	 */
 	function _getHashPath() {
 		global $wgMathDirectory;
 		$path = $wgMathDirectory .'/'. substr($this->hash, 0, 1)
@@ -249,13 +697,18 @@
 		return $path;
 	}
 
-
 }
 
+/**
+ * Render a LaTeX fragment.
+ * @param $tex String containing the LaTeX fragment.
+ * @return String containing an HTML fragment representing the formula
+ * specified in $tex.
+ */
 function renderMath( $tex ) {
 	global $wgUser;
 	$math = new MathRenderer( $tex );
-	$math->setOutputMode( $wgUser->getOption('math'));
+	$math->setOutputMode( $wgUser->getOption( 'math' ) );
 	return $math->render();
 }
 
diff -ur phase3/includes/OutputPage.php blahtex/includes/OutputPage.php
--- phase3/includes/OutputPage.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/OutputPage.php	2006-05-20 01:26:34.000000000 +1000
@@ -581,7 +581,19 @@
 		# Disable temporary placeholders, so that the skin produces HTML
 		$sk->postParseLinkColour( false );
 
-		header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
+		/* Send page as XHTML if the user has selected MathML and the browser accepts XHTML */
+                if ( $wgUser->getOption( 'math' ) == MW_MATH_MATHML ) {
+                        if ( isset( $_SERVER['HTTP_ACCEPT'] ) && stristr( $_SERVER['HTTP_ACCEPT'], 'application/xhtml+xml' )) {
+                                header( "Content-type: application/xhtml+xml; charset={$wgOutputEncoding}" );
+                        } else if ( isset( $_SERVER["HTTP_USER_AGENT"] ) && stristr( $_SERVER["HTTP_USER_AGENT"], "MathPlayer" )) {
+                                header( "Content-type: application/xhtml+xml" );
+                        } else {
+                                header( "Content-type: text/html; charset={$wgOutputEncoding}" );
+                        }
+                } else {
+                        header( "Content-type: text/html; charset={$wgOutputEncoding}" );
+                }
+
 		header( 'Content-language: '.$wgContLanguageCode );
 
 		if ($this->mArticleBodyOnly) {
@@ -949,14 +961,23 @@
 		global $wgDocType, $wgDTD, $wgContLanguageCode, $wgOutputEncoding, $wgMimeType;
 		global $wgUser, $wgContLang, $wgUseTrackbacks, $wgTitle;
 
-		if( $wgMimeType == 'text/xml' || $wgMimeType == 'application/xhtml+xml' || $wgMimeType == 'application/xml' ) {
-			$ret = "<?xml version=\"1.0\" encoding=\"$wgOutputEncoding\" ?>\n";
-		} else {
-			$ret = '';
+                /* If the user has selected MathML, then we should prepare an XHTML page */
+		if( $wgUser->getOption('math') == MW_MATH_MATHML ) {
+			$ret = "<?xml version=\"1.0\" encoding=\"$wgOutputEncoding\"?>\n"
+				. "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN\"\n"
+				. "        \"http://www.w3.org/Math/DTD/mathml2/xhtml-math11-f.dtd\">\n";
+			array_push( $this->mMetatags, array( "http:Content-type", 
+							     "application/xhtml+xml; charset={$wgOutputEncoding}" ) );
+		} else { 
+			if( $wgMimeType == 'text/xml' || $wgMimeType == 'application/xhtml+xml' || $wgMimeType == 'application/xml' ) {
+				$ret = "<?xml version=\"1.0\" encoding=\"$wgOutputEncoding\" ?>\n";
+			} else {
+				$ret = '';
+			}
+			$ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\"\n        \"$wgDTD\">\n";
+			array_push( $this->mMetatags, array( "http:Content-type", "$wgMimeType; charset={$wgOutputEncoding}" ) );
 		}
 
-		$ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\"\n        \"$wgDTD\">\n";
-
 		if ( '' == $this->getHTMLTitle() ) {
 			$this->setHTMLTitle(  wfMsg( 'pagetitle', $this->getPageTitle() ));
 		}
@@ -964,7 +985,6 @@
 		$rtl = $wgContLang->isRTL() ? " dir='RTL'" : '';
 		$ret .= "<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"$wgContLanguageCode\" lang=\"$wgContLanguageCode\" $rtl>\n";
 		$ret .= "<head>\n<title>" . htmlspecialchars( $this->getHTMLTitle() ) . "</title>\n";
-		array_push( $this->mMetatags, array( "http:Content-type", "$wgMimeType; charset={$wgOutputEncoding}" ) );
 
 		$ret .= $this->getHeadLinks();
 		global $wgStylePath;
diff -ur phase3/includes/Parser.php blahtex/includes/Parser.php
--- phase3/includes/Parser.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/Parser.php	2006-05-20 01:26:36.000000000 +1000
@@ -334,7 +334,7 @@
 			$start = "/<$tag(\\s+[^>]*|\\s*\/?)>/i";
 			$end   = "/<\\/$tag\\s*>/i";
 		}
-
+		
 		while ( '' != $text ) {
 			$p = preg_split( $start, $text, 2, PREG_SPLIT_DELIM_CAPTURE );
 			$stripped .= $p[0];
@@ -359,7 +359,6 @@
 			$params[$marker] = Sanitizer::decodeTagAttributes( $attributes );
 
 			if ( $empty === '/' ) {
-				// Empty element tag, <tag />
 				$content[$marker] = null;
 				$text = $inside;
 			} else {
@@ -622,6 +621,9 @@
 	 * will be used depending on availability. Override the default
 	 * $wgTidyInternal setting to disable the internal if it's not working.
 	 *
+	 * Since html tidy does not understand MathML, we temporarily replace
+	 * all <math>...</math> with placeholders.
+	 *
 	 * @param string $text Hideous HTML input
 	 * @return string Corrected HTML output
 	 * @public
@@ -629,6 +631,9 @@
 	 */
 	function tidy( $text ) {
 		global $wgTidyInternal;
+		$math_content = array();
+		$text = Parser::extractTagsAndParams( 'math', $text, $math_content,
+						      $math_tags, $math_params, $this->mUniqPrefix );
 		$wrappedtext = '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"'.
 ' "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html>'.
 '<head><title>test</title></head><body>'.$text.'</body></html>';
@@ -641,6 +646,10 @@
 			wfDebug( "Tidy error detected!\n" );
 			return $text . "\n<!-- Tidy found serious XHTML errors -->\n";
 		}
+		foreach( $math_content as $marker => $content ) {
+			$full_tag = $math_tags[$marker] . $content . "</math>";
+			$correctedtext = str_replace( $marker, $full_tag, $correctedtext );
+		}
 		return $correctedtext;
 	}
 
@@ -685,6 +694,7 @@
 		if( $cleansource == '' && $text != '') {
 			// Some kind of error happened, so we couldn't get the corrected text.
 			// Just give up; we'll use the source text and append a warning.
+			wfDebug("tidy invocation: $wgTidyBin -config $wgTidyConf $wgTidyOpts$opts\n");
 			return null;
 		} else {
 			return $cleansource;
diff -ur phase3/includes/Sanitizer.php blahtex/includes/Sanitizer.php
--- phase3/includes/Sanitizer.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/Sanitizer.php	2006-05-20 01:26:36.000000000 +1000
@@ -314,7 +314,93 @@
 	'Zeta'     => 918,
 	'zeta'     => 950,
 	'zwj'      => 8205,
-	'zwnj'     => 8204 );
+        'zwnj'     => 8204,
+	/* Plane-1 entities for MathML. */
+        'Ascr'     => 0x1D49C, 
+        'Cscr'     => 0x1D49E, 
+        'Dscr'     => 0x1D49F, 
+        'Gscr'     => 0x1D4A2, 
+        'Jscr'     => 0x1D4A5, 
+        'Kscr'     => 0x1D4A6, 
+        'Nscr'     => 0x1D4A9, 
+        'Oscr'     => 0x1D4AA, 
+        'Pscr'     => 0x1D4AB, 
+        'Qscr'     => 0x1D4AC, 
+        'Sscr'     => 0x1D4AE, 
+        'Tscr'     => 0x1D4AF, 
+        'Uscr'     => 0x1D4B0, 
+        'Vscr'     => 0x1D4B1, 
+        'Wscr'     => 0x1D4B2, 
+        'Xscr'     => 0x1D4B3, 
+        'Yscr'     => 0x1D4B4, 
+        'Zscr'     => 0x1D4B5, 
+        'Afr'      => 0x1D504, 
+        'Bfr'      => 0x1D505, 
+        'Dfr'      => 0x1D507, 
+        'Efr'      => 0x1D508, 
+        'Ffr'      => 0x1D509, 
+        'Gfr'      => 0x1D50A, 
+        'Jfr'      => 0x1D50D, 
+        'Kfr'      => 0x1D50E, 
+        'Lfr'      => 0x1D50F, 
+        'Mfr'      => 0x1D510, 
+        'Nfr'      => 0x1D511, 
+        'Ofr'      => 0x1D512, 
+        'Pfr'      => 0x1D513, 
+        'Qfr'      => 0x1D514, 
+        'Sfr'      => 0x1D516, 
+        'Tfr'      => 0x1D517, 
+        'Ufr'      => 0x1D518, 
+        'Vfr'      => 0x1D519, 
+        'Wfr'      => 0x1D51A, 
+        'Xfr'      => 0x1D51B, 
+        'Yfr'      => 0x1D51C, 
+        'afr'      => 0x1D51E, 
+        'bfr'      => 0x1D51F, 
+        'cfr'      => 0x1D520, 
+        'dfr'      => 0x1D521, 
+        'efr'      => 0x1D522, 
+        'ffr'      => 0x1D523, 
+        'gfr'      => 0x1D524, 
+        'hfr'      => 0x1D525, 
+        'ifr'      => 0x1D526, 
+        'jfr'      => 0x1D527, 
+        'kfr'      => 0x1D528, 
+        'lfr'      => 0x1D529, 
+        'mfr'      => 0x1D52A, 
+        'nfr'      => 0x1D52B, 
+        'ofr'      => 0x1D52C, 
+        'pfr'      => 0x1D52D, 
+        'qfr'      => 0x1D52E, 
+        'rfr'      => 0x1D52F, 
+        'sfr'      => 0x1D530, 
+        'tfr'      => 0x1D531, 
+        'ufr'      => 0x1D532, 
+        'vfr'      => 0x1D533, 
+        'wfr'      => 0x1D534, 
+        'xfr'      => 0x1D535, 
+        'yfr'      => 0x1D536, 
+        'zfr'      => 0x1D537, 
+        'Aopf'     => 0x1D538, 
+        'Bopf'     => 0x1D539, 
+        'Dopf'     => 0x1D53B, 
+        'Eopf'     => 0x1D53C, 
+        'Fopf'     => 0x1D53D, 
+        'Gopf'     => 0x1D53E, 
+        'Iopf'     => 0x1D540, 
+        'Jopf'     => 0x1D541, 
+        'Kopf'     => 0x1D542, 
+        'Lopf'     => 0x1D543, 
+        'Mopf'     => 0x1D544, 
+        'Oopf'     => 0x1D546, 
+        'Sopf'     => 0x1D54A, 
+        'Topf'     => 0x1D54B, 
+        'Uopf'     => 0x1D54C, 
+        'Vopf'     => 0x1D54D, 
+        'Wopf'     => 0x1D54E, 
+        'Xopf'     => 0x1D54F, 
+        'Yopf'     => 0x1D550
+);
 
 /** @package MediaWiki */
 class Sanitizer {
diff -ur phase3/includes/SkinTemplate.php blahtex/includes/SkinTemplate.php
--- phase3/includes/SkinTemplate.php	2006-05-20 00:57:37.000000000 +1000
+++ blahtex/includes/SkinTemplate.php	2006-05-20 01:26:37.000000000 +1000
@@ -137,7 +137,7 @@
 		global $wgScript, $wgStylePath, $wgContLanguageCode;
 		global $wgMimeType, $wgJsMimeType, $wgOutputEncoding, $wgRequest;
 		global $wgDisableCounters, $wgLogo, $action, $wgFeedClasses, $wgHideInterlanguageLinks;
-		global $wgMaxCredits, $wgShowCreditsIfMax;
+		global $wgMaxCredits, $wgShowCreditsIfMax, $wgDocType, $wgDTD;;
 		global $wgPageShowWatchingUsers;
 		global $wgUseTrackbacks;
 		global $wgDBname;
@@ -219,7 +219,19 @@
 		if ($wgUseTrackbacks && $out->isArticleRelated())
 			$tpl->set( 'trackbackhtml', $wgTitle->trackbackRDF());
 
-		$tpl->setRef( 'mimetype', $wgMimeType );
+                /* If the user has selected MathML, then we should prepare an XHTML page */
+                if( $wgUser->getOption('math') == MW_MATH_MATHML ) {
+                        $tpl->set( 'mimetype', 'application/xhtml+xml' );
+                        $tpl->set( 'doctype', '-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN' );
+                        $tpl->set( 'dtd', 'http://www.w3.org/Math/DTD/mathml2/xhtml-math11-f.dtd' );
+                        $tpl->set( 'xmlheaders', "<?xml version=\"1.0\" encoding=\"$wgOutputEncoding\"?>\n" );
+                } else {
+                        $tpl->setRef( 'mimetype', $wgMimeType );
+                        $tpl->set( 'doctype', '-//W3C//DTD XHTML 1.0 Transitional//EN' );
+                        $tpl->set( 'dtd', 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd' );
+                        $tpl->set( 'xmlheaders', '' );
+                }
+
 		$tpl->setRef( 'jsmimetype', $wgJsMimeType );
 		$tpl->setRef( 'charset', $wgOutputEncoding );
 		$tpl->set( 'headlinks', $out->getHeadLinks() );
diff -ur phase3/languages/Messages.php blahtex/languages/Messages.php
--- phase3/languages/Messages.php	2006-05-20 00:58:50.000000000 +1000
+++ blahtex/languages/Messages.php	2006-05-20 01:46:07.000000000 +1000
@@ -678,15 +678,6 @@
 'dateformat'		=> 'Date format',
 'datedefault'		=> 'No preference',
 'datetime'		=> 'Date and time',
-'math_failure'		=> 'Failed to parse',
-'math_unknown_error'	=> 'unknown error',
-'math_unknown_function'	=> 'unknown function',
-'math_lexing_error'	=> 'lexing error',
-'math_syntax_error'	=> 'syntax error',
-'math_image_error'	=> 'PNG conversion failed; check for correct installation of latex, dvips, gs, and convert',
-'math_bad_tmpdir'	=> 'Can\'t write to or create math temp directory',
-'math_bad_output'	=> 'Can\'t write to or create math output directory',
-'math_notexvc'	=> 'Missing texvc executable; please see math/README to configure.',
 'prefs-personal' => 'User profile',
 'prefs-rc' => 'Recent changes',
 'prefs-watchlist' => 'Watchlist',
@@ -719,6 +710,94 @@
 'default'		=> 'default',
 'files'			=> 'Files',
 
+# Mathematics
+#
+
+'math_failure'		=> 'Failed to parse',
+'math_unknown_error'	=> 'unknown error$1',
+'math_unknown_function'	=> 'unknown function ',
+'math_input_error'	=> 'input error',
+'math_lexing_error'	=> 'lexing error $1',
+'math_syntax_error'	=> 'syntax error $1',
+'math_image_error'	=> 'PNG conversion failed; check for correct installation of latex, dvips, gs, and convert',
+'math_bad_tmpdir'	=> 'Can\'t write to or create math temp directory',
+'math_bad_output'	=> 'Can\'t write to or create math output directory',
+'math_notexvc'	        => 'Missing texvc executable; please see math/README to configure.',
+'math_noblahtex'        => 'Can\'t execute blahtex, which should be at $1',
+
+# Blahtex messages
+'math_AmbiguousInfix'                   => 'Ambiguous placement of "$1" ' .
+                                           '(try using additional braces "{ ... }" to disambiguate)',
+'math_CannotChangeDirectory'            => 'Cannot change working directory',
+'math_CannotCreateTexFile'              => 'Cannot create tex file',
+'math_CannotRunDvipng'                  => 'Cannot run dvipng',
+'math_CannotRunLatex'                   => 'Cannot run latex',
+'math_CannotWritePngDirectory'          => ' Cannot write to output PNG directory',
+'math_CannotWriteTexFile'               => 'Cannot write to tex file',
+'math_CasesRowTooBig'                   => 'There can only be two entries in each row of a "cases" block',
+'math_DoubleSubscript'                  => 'Encountered two subscripts attached to the same base ' .
+                                           '(only one is allowed)',
+'math_DoubleSuperscript'                => 'Encountered two superscripts attached to the same base ' .
+                                           '(only one is allowed)',
+'math_IllegalCharacter'                 => 'Illegal character in input',
+'math_IllegalCommandInMathMode'         => 'The command "$1" is illegal in math mode',
+'math_IllegalCommandInMathModeWithHint' => 'The command "$1" is illegal in math mode ' .
+                                           '(perhaps you intended to use "$2" instead?)',
+'math_IllegalCommandInTextMode'         => 'The command "$1" is illegal in text mode',
+'math_IllegalCommandInTextModeWithHint' => 'The command "$1" is illegal in text mode ' .
+                                           '(perhaps you intended to use "$2" instead?)',
+'math_IllegalDelimiter'                 => 'Illegal delimiter following "$1"',
+'math_IllegalFinalBackslash'            => 'Illegal backslash "\\" at end of input',
+'math_IllegalNestedFontEncodings'       => 'Font encoding commands may not be nested',
+'math_IllegalRedefinition'              => 'The command "$1" has already been defined; you cannot redefine it',
+'math_InvalidColour'                    => 'The colour "$1" is invalid',
+'math_InvalidUtf8Input'                 => 'The input string was not valid UTF-8',
+'math_LatexFontNotSpecified'            => 'No LaTeX font has been specified for "$1"',
+'math_LatexPackageUnavailable'          => 'Unable to render PNG because the LaTeX package "$1" is unavailable',
+'math_MismatchedBeginAndEnd'            => 'Commands "$1" and "$2" do not match',
+'math_MisplacedLimits'                  => 'The command "$1" can only appear after a math operator ' .
+                                           '(consider using "\\mathop")',
+'math_MissingCommandAfterNewcommand'    => 'Missing or illegal new command name after "\\newcommand" ' .
+                                           '(there must be precisely one command defined; it must begin ' .
+                                           'with a backslash "\\" and contain only alphabetic characters)',
+'math_MissingDelimiter'                 => 'Missing delimiter after "$1"',
+'math_MissingOpenBraceAfter'            => 'Missing open brace "{" after "$1"',
+'math_MissingOpenBraceAtEnd'            => 'Missing open brace "{" at end of input',
+'math_MissingOpenBraceBefore'           => 'Missing open brace "{" before "$1"',
+'math_MissingOrIllegalParameterCount'   => 'Missing or illegal parameter count in definition of "$1" ' .
+                                           '(must be a single digit between 1 and 9 inclusive)',
+'math_MissingOrIllegalParameterIndex'   => 'Missing or illegal parameter index in definition of "$1"',
+'math_NonAsciiInMathMode'               => 'Non-ASCII characters may only be used in text mode ' .
+                                           '(try enclosing the problem characters in "\\text{...}")',
+'math_NotEnoughArguments'               => 'Not enough arguments were supplied for "$1"',
+'math_PngIncompatibleCharacter'         => 'Unable to correctly generate PNG containing the character $1',
+'math_ReservedCommand'                  => 'The command "$1" is reserved for internal use by blahtex',
+'math_SubstackRowTooBig'                => 'There can only be one entry in each row of a "substack" block',
+'math_TooManyMathmlNodes'               => 'There are too many nodes in the MathML tree',
+'math_TooManyTokens'                    => 'The input is too long',
+'math_UnavailableSymbolFontCombination' => 'The symbol "$1" is not available in the font "$2"',
+'math_UnexpectedNextCell'               => 'The command "&" may only appear inside a "\\begin ... \\end" block',
+'math_UnexpectedNextRow'                => 'The command "\\\\" may only appear inside a "\\begin ... \\end" block',
+'math_UnmatchedBegin'                   => 'Encountered "\\begin" without matching "\\end"',
+'math_UnmatchedCloseBrace'              => 'Encountered close brace "}" without matching open brace "{"',
+'math_UnmatchedEnd'                     => 'Encountered "\\end" without matching "\\begin"',
+'math_UnmatchedLeft'                    => 'Encountered "\\left" without matching "\\right"',
+'math_UnmatchedOpenBrace'               => 'Encountered open brace "{" without matching close brace "}"',
+'math_UnmatchedOpenBracket'             => 'Encountered open bracket "[" without matching close bracket "]"',
+'math_UnmatchedRight'                   => 'Encountered "\\right" without matching "\\left"',
+'math_UnrecognisedCommand'              => 'Unrecognised command "$1"',
+'WrongFontEncoding'                     => 'The symbol "$1" may not appear in font encoding "$2"',
+'WrongFontEncodingWithHint'             => 'The symbol "$1" may not appear in font encoding "$2" (try using the "$3{...}" command)',
+
+# User levels special page
+#
+
+# switching pan
+'groups-lookup-group' => 'Manage group rights',
+'groups-group-edit' => 'Existing groups:',
+'editgroup' => 'Edit Group',
+'addgroup' => 'Add Group',
+
 # User rights
 'userrights-lookup-user' => 'Manage user groups',
 'userrights-user-editname' => 'Enter a username:',
@@ -1505,7 +1584,7 @@
 'mw_math_html' => 'HTML if possible or else PNG',
 'mw_math_source' => 'Leave it as TeX (for text browsers)',
 'mw_math_modern' => 'Recommended for modern browsers',
-'mw_math_mathml' => 'MathML if possible (experimental)',
+'mw_math_mathml' => 'MathML (experimental)',
 
 # Patrolling
 'markaspatrolleddiff'   => "Mark as patrolled",
diff -ur phase3/skins/MonoBook.php blahtex/skins/MonoBook.php
--- phase3/skins/MonoBook.php	2006-05-20 00:56:56.000000000 +1000
+++ blahtex/skins/MonoBook.php	2006-05-20 01:26:42.000000000 +1000
@@ -50,7 +50,9 @@
 		// Suppress warnings to prevent notices about missing indexes in $this->data
 		wfSuppressWarnings();
 
-?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+?><?php $this->html('xmlheaders');
+?><!DOCTYPE html PUBLIC "<?php $this->text('doctype'); ?>"
+           "<?php $this->text('dtd'); ?>">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="<?php $this->text('lang') ?>" lang="<?php $this->text('lang') ?>" dir="<?php $this->text('dir') ?>">
 	<head>
 		<meta http-equiv="Content-Type" content="<?php $this->text('mimetype') ?>; charset=<?php $this->text('charset') ?>" />