diff --git a/Doxyfile b/Doxyfile
new file mode 100644
index 00000000..bfdd6b5d
--- /dev/null
+++ b/Doxyfile
@@ -0,0 +1,236 @@
+# Doxyfile 1.4.7
+
+#---------------------------------------------------------------------------
+# Project related configuration options
+#---------------------------------------------------------------------------
+PROJECT_NAME           = HTMLPurifier
+PROJECT_NUMBER         = trunk
+OUTPUT_DIRECTORY       = "C:/Documents and Settings/Edward/My Documents/My Webs/htmlpurifier/docs/doxygen"
+CREATE_SUBDIRS         = NO
+OUTPUT_LANGUAGE        = English
+USE_WINDOWS_ENCODING   = NO
+BRIEF_MEMBER_DESC      = YES
+REPEAT_BRIEF           = YES
+ABBREVIATE_BRIEF       = "The $name class" \
+                         "The $name widget" \
+                         "The $name file" \
+                         is \
+                         provides \
+                         specifies \
+                         contains \
+                         represents \
+                         a \
+                         an \
+                         the
+ALWAYS_DETAILED_SEC    = NO
+INLINE_INHERITED_MEMB  = NO
+FULL_PATH_NAMES        = YES
+STRIP_FROM_PATH        = "C:/Documents and Settings/Edward/My Documents/My Webs/htmlpurifier"
+STRIP_FROM_INC_PATH    = 
+SHORT_NAMES            = NO
+JAVADOC_AUTOBRIEF      = YES
+MULTILINE_CPP_IS_BRIEF = NO
+DETAILS_AT_TOP         = NO
+INHERIT_DOCS           = YES
+SEPARATE_MEMBER_PAGES  = NO
+TAB_SIZE               = 4
+ALIASES                = 
+OPTIMIZE_OUTPUT_FOR_C  = NO
+OPTIMIZE_OUTPUT_JAVA   = NO
+BUILTIN_STL_SUPPORT    = NO
+DISTRIBUTE_GROUP_DOC   = NO
+SUBGROUPING            = YES
+#---------------------------------------------------------------------------
+# Build related configuration options
+#---------------------------------------------------------------------------
+EXTRACT_ALL            = YES
+EXTRACT_PRIVATE        = YES
+EXTRACT_STATIC         = YES
+EXTRACT_LOCAL_CLASSES  = YES
+EXTRACT_LOCAL_METHODS  = NO
+HIDE_UNDOC_MEMBERS     = NO
+HIDE_UNDOC_CLASSES     = NO
+HIDE_FRIEND_COMPOUNDS  = NO
+HIDE_IN_BODY_DOCS      = NO
+INTERNAL_DOCS          = NO
+CASE_SENSE_NAMES       = YES
+HIDE_SCOPE_NAMES       = NO
+SHOW_INCLUDE_FILES     = YES
+INLINE_INFO            = YES
+SORT_MEMBER_DOCS       = YES
+SORT_BRIEF_DOCS        = NO
+SORT_BY_SCOPE_NAME     = NO
+GENERATE_TODOLIST      = YES
+GENERATE_TESTLIST      = YES
+GENERATE_BUGLIST       = YES
+GENERATE_DEPRECATEDLIST= YES
+ENABLED_SECTIONS       = 
+MAX_INITIALIZER_LINES  = 30
+SHOW_USED_FILES        = YES
+SHOW_DIRECTORIES       = NO
+FILE_VERSION_FILTER    = 
+#---------------------------------------------------------------------------
+# configuration options related to warning and progress messages
+#---------------------------------------------------------------------------
+QUIET                  = NO
+WARNINGS               = YES
+WARN_IF_UNDOCUMENTED   = YES
+WARN_IF_DOC_ERROR      = YES
+WARN_NO_PARAMDOC       = NO
+WARN_FORMAT            = "$file:$line: $text"
+WARN_LOGFILE           = 
+#---------------------------------------------------------------------------
+# configuration options related to the input files
+#---------------------------------------------------------------------------
+INPUT                  = "C:/Documents and Settings/Edward/My Documents/My Webs/htmlpurifier"
+FILE_PATTERNS          = *.php
+RECURSIVE              = YES
+EXCLUDE                = 
+EXCLUDE_SYMLINKS       = NO
+EXCLUDE_PATTERNS       = */tests/* \
+                         */benchmarks/*
+EXAMPLE_PATH           = 
+EXAMPLE_PATTERNS       = *
+EXAMPLE_RECURSIVE      = NO
+IMAGE_PATH             = 
+INPUT_FILTER           = 
+FILTER_PATTERNS        = 
+FILTER_SOURCE_FILES    = NO
+#---------------------------------------------------------------------------
+# configuration options related to source browsing
+#---------------------------------------------------------------------------
+SOURCE_BROWSER         = YES
+INLINE_SOURCES         = NO
+STRIP_CODE_COMMENTS    = YES
+REFERENCED_BY_RELATION = YES
+REFERENCES_RELATION    = YES
+REFERENCES_LINK_SOURCE = YES
+USE_HTAGS              = NO
+VERBATIM_HEADERS       = YES
+#---------------------------------------------------------------------------
+# configuration options related to the alphabetical class index
+#---------------------------------------------------------------------------
+ALPHABETICAL_INDEX     = NO
+COLS_IN_ALPHA_INDEX    = 5
+IGNORE_PREFIX          = 
+#---------------------------------------------------------------------------
+# configuration options related to the HTML output
+#---------------------------------------------------------------------------
+GENERATE_HTML          = YES
+HTML_OUTPUT            = html
+HTML_FILE_EXTENSION    = .html
+HTML_HEADER            = 
+HTML_FOOTER            = 
+HTML_STYLESHEET        = 
+HTML_ALIGN_MEMBERS     = YES
+GENERATE_HTMLHELP      = NO
+CHM_FILE               = 
+HHC_LOCATION           = 
+GENERATE_CHI           = NO
+BINARY_TOC             = NO
+TOC_EXPAND             = NO
+DISABLE_INDEX          = NO
+ENUM_VALUES_PER_LINE   = 4
+GENERATE_TREEVIEW      = YES
+TREEVIEW_WIDTH         = 250
+#---------------------------------------------------------------------------
+# configuration options related to the LaTeX output
+#---------------------------------------------------------------------------
+GENERATE_LATEX         = NO
+LATEX_OUTPUT           = latex
+LATEX_CMD_NAME         = latex
+MAKEINDEX_CMD_NAME     = makeindex
+COMPACT_LATEX          = NO
+PAPER_TYPE             = a4wide
+EXTRA_PACKAGES         = 
+LATEX_HEADER           = 
+PDF_HYPERLINKS         = YES
+USE_PDFLATEX           = YES
+LATEX_BATCHMODE        = NO
+LATEX_HIDE_INDICES     = NO
+#---------------------------------------------------------------------------
+# configuration options related to the RTF output
+#---------------------------------------------------------------------------
+GENERATE_RTF           = NO
+RTF_OUTPUT             = rtf
+COMPACT_RTF            = NO
+RTF_HYPERLINKS         = NO
+RTF_STYLESHEET_FILE    = 
+RTF_EXTENSIONS_FILE    = 
+#---------------------------------------------------------------------------
+# configuration options related to the man page output
+#---------------------------------------------------------------------------
+GENERATE_MAN           = NO
+MAN_OUTPUT             = man
+MAN_EXTENSION          = .3
+MAN_LINKS              = NO
+#---------------------------------------------------------------------------
+# configuration options related to the XML output
+#---------------------------------------------------------------------------
+GENERATE_XML           = NO
+XML_OUTPUT             = xml
+XML_SCHEMA             = 
+XML_DTD                = 
+XML_PROGRAMLISTING     = YES
+#---------------------------------------------------------------------------
+# configuration options for the AutoGen Definitions output
+#---------------------------------------------------------------------------
+GENERATE_AUTOGEN_DEF   = NO
+#---------------------------------------------------------------------------
+# configuration options related to the Perl module output
+#---------------------------------------------------------------------------
+GENERATE_PERLMOD       = NO
+PERLMOD_LATEX          = NO
+PERLMOD_PRETTY         = YES
+PERLMOD_MAKEVAR_PREFIX = 
+#---------------------------------------------------------------------------
+# Configuration options related to the preprocessor   
+#---------------------------------------------------------------------------
+ENABLE_PREPROCESSING   = YES
+MACRO_EXPANSION        = NO
+EXPAND_ONLY_PREDEF     = NO
+SEARCH_INCLUDES        = YES
+INCLUDE_PATH           = 
+INCLUDE_FILE_PATTERNS  = 
+PREDEFINED             = 
+EXPAND_AS_DEFINED      = 
+SKIP_FUNCTION_MACROS   = YES
+#---------------------------------------------------------------------------
+# Configuration::additions related to external references   
+#---------------------------------------------------------------------------
+TAGFILES               = 
+GENERATE_TAGFILE       = 
+ALLEXTERNALS           = NO
+EXTERNAL_GROUPS        = YES
+PERL_PATH              = /usr/bin/perl
+#---------------------------------------------------------------------------
+# Configuration options related to the dot tool   
+#---------------------------------------------------------------------------
+CLASS_DIAGRAMS         = YES
+HIDE_UNDOC_RELATIONS   = YES
+HAVE_DOT               = NO
+CLASS_GRAPH            = YES
+COLLABORATION_GRAPH    = YES
+GROUP_GRAPHS           = YES
+UML_LOOK               = NO
+TEMPLATE_RELATIONS     = NO
+INCLUDE_GRAPH          = YES
+INCLUDED_BY_GRAPH      = YES
+CALL_GRAPH             = NO
+CALLER_GRAPH           = NO
+GRAPHICAL_HIERARCHY    = YES
+DIRECTORY_GRAPH        = YES
+DOT_IMAGE_FORMAT       = png
+DOT_PATH               = 
+DOTFILE_DIRS           = 
+MAX_DOT_GRAPH_WIDTH    = 1024
+MAX_DOT_GRAPH_HEIGHT   = 1024
+MAX_DOT_GRAPH_DEPTH    = 1000
+DOT_TRANSPARENT        = NO
+DOT_MULTI_TARGETS      = NO
+GENERATE_LEGEND        = YES
+DOT_CLEANUP            = YES
+#---------------------------------------------------------------------------
+# Configuration::additions related to the search engine   
+#---------------------------------------------------------------------------
+SEARCHENGINE           = NO
diff --git a/library/HTMLPurifier.php b/library/HTMLPurifier.php
index c6577ae4..4b3f2eee 100644
--- a/library/HTMLPurifier.php
+++ b/library/HTMLPurifier.php
@@ -1,22 +1,62 @@
 <?php
 
+/*!
+ * @mainpage
+ * 
+ * HTMLPurifier is a purification class that will take an arbitrary snippet of
+ * HTML and rigorously test, validate and filter it into a version that
+ * is safe for output onto webpages. It achieves this by:
+ * 
+ *  -# Lexing (parsing into tokens) the document,
+ *  -# Removing all elements not in the whitelist,
+ *  -# Making the tokens well-formed,
+ *  -# Fixing the nesting of the nodes,
+ *  -# Validating attributes of the nodes, and
+ *  -# Generating HTML from the purified tokens.
+ * 
+ * See /docs/spec.txt for more details.
+ */
+
 require_once 'HTMLPurifier/Lexer.php';
 require_once 'HTMLPurifier/Definition.php';
 require_once 'HTMLPurifier/Generator.php';
 
+/**
+ * Main library execution class.
+ * 
+ * Facade that performs calls to the HTMLPurifier_Lexer,
+ * HTMLPurifier_Definition and HTMLPurifier_Generator subsystems in order to
+ * purify HTML.
+ */
 class HTMLPurifier
 {
     
-    var $lexer;
-    var $definition;
-    var $generator;
+    var $lexer;         /*!< @brief Instance of HTMLPurifier_Lexer concrete
+                                    implementation. */
+    var $definition;    /*!< @brief Instance of HTMLPurifier_Definition. */
+    var $generator;     /*!< @brief Instance of HTMLPurifier_Generator. */
     
+    /**
+     * Initializes the purifier.
+     * 
+     * The constructor instantiates all necessary sub-objects to do the job,
+     * because creating some of them (esp. HTMLPurifier_Definition) can be
+     * expensive.
+     * 
+     * @todo Accept Policy object to define configuration.
+     */
     function HTMLPurifier() {
-        $this->lexer        = new HTMLPurifier_Lexer();
+        $this->lexer        = new HTMLPurifier_Lexer::create();
         $this->definition   = new HTMLPurifier_Definition();
         $this->generator    = new HTMLPurifier_Generator();
     }
     
+    /**
+     * Purifies HTML.
+     * 
+     * @param $html String of HTML to purify
+     * @return Purified HTML
+     */
     function purify($html) {
         $tokens = $this->lexer->tokenizeHTML($html);
         $tokens = $this->definition->purifyTokens($tokens);
diff --git a/library/HTMLPurifier/Lexer.php b/library/HTMLPurifier/Lexer.php
index c6bc4f71..2a8f37a5 100644
--- a/library/HTMLPurifier/Lexer.php
+++ b/library/HTMLPurifier/Lexer.php
@@ -1,21 +1,74 @@
 <?php
 
-/**
- * Forgivingly lexes HTML (not XML, since it doesn't adhere to spec exactly)
- */
-
 require_once 'HTMLPurifier/Token.php';
 
+/**
+ * Forgivingly lexes HTML (SGML-style) markup into tokens.
+ * 
+ * The lexer parses a string of SGML-style markup and converts them into
+ * corresponding tokens.  It doesn't check for well-formedness, although it's
+ * internal mechanism may make this automatic (such as the case of
+ * HTMLPurifier_Lexer_DOMLex).  There are several implementations to choose
+ * from.
+ * 
+ * The lexer is HTML-oriented: it might work with XML, but it's not
+ * recommended, as we adhere to a subset of the specification for optimization
+ * reasons.
+ * 
+ * This class cannot be directly instantiated, but you may use create() to
+ * retrieve a default copy of the lexer.
+ * 
+ * @note
+ * We use tokens rather than create a DOM representation because DOM would:
+ * 
+ * @note
+ *  -# Require more processing power to create,
+ *  -# Require recursion to iterate,
+ *  -# Must be compatible with PHP 5's DOM (otherwise duplication),
+ *  -# Has the entire document structure (html and body not needed), and
+ *  -# Has unknown readability improvement.
+ * 
+ * @note
+ * What the last item means is that the functions for manipulating tokens are
+ * already fairly compact, and when well-commented, more abstraction may not
+ * be needed.
+ * 
+ * @see HTMLPurifier_Token
+ */
 class HTMLPurifier_Lexer
 {
     
+    /**
+     * Lexes an HTML string into tokens.
+     * 
+     * @param $string String HTML.
+     * @return HTMLPurifier_Token array representation of HTML.
+     */
     function tokenizeHTML($string) {
         trigger_error('Call to abstract class', E_USER_ERROR);
     }
     
-    // we don't really care if it's a reference or a copy
-    
+    /**
+     * Retrieves or sets the default Lexer as a Prototype Factory.
+     * 
+     * Depending on what PHP version you are running, the abstract base
+     * Lexer class will determine which concrete Lexer is best for you:
+     * HTMLPurifier_Lexer_DirectLex for PHP 4, and HTMLPurifier_Lexer_DOMLex
+     * for PHP 5 and beyond.
+     * 
+     * Passing the optional prototype lexer parameter will override the
+     * default with your own implementation.  A copy/reference of the prototype
+     * lexer will now be returned when you request a new lexer.
+     * 
+     * @note
+     * Though it is possible to call this factory method from subclasses,
+     * such usage is not recommended.
+     * 
+     * @param $prototype Optional prototype lexer.
+     * @return Concrete lexer.
+     */
     function create($prototype = null) {
+        // we don't really care if it's a reference or a copy
         static $lexer = null;
         if ($prototype) {
             $lexer = $prototype;