Take from: http://code.google.com/p/synweb/
SynWeb is an advanced highlighter for (Uni)SynEdit for PHP, (X)HTML, WML, CSS, JS. It has much more features than TSynMultiSyn and works about 2-10 times faster. Included also SynTokenMatch - inteligment brace/token matching, html tags, begin->end, etc.)

Some SynWeb features:

    support for embedded:
        PHP, CSS, JS in XHTML/HTML
        PHP in CSS (.css), JS (.js), WML 
    support for ANSI and Unicode version of SynEdit
    faster about 2-10 times than using TSynMultiSyn
    full validation for tags (also checks for valid '/>' or '/') and its attributes for HTML across difference versions (for XHTML - case sensitive)
    values in tags without quotation are also highlighted as ValueAttrib (only in HTML, in XHTML is highlighted as error because, XHTML doesn't allow for unquoted values)
    support for WML 1.1/1.2/1.3
    in CSS validation for tags (you can set also HTML version)
    validation for special entity characters (eg. &, ©)
    almost FULL validation for CSS across CSS1 and CSS2.1
    support for

    <script language="php">

    as start tag for PHP (also <?, <?php, <?=, <%)
    end tags for PHP doesn't stop in strings, comments (stops only in singleline), etc, you can now write "<?xml ... ?>" and PHP mode doesn't stop,
    support for custom HEREDOC names (defined in TStringList, or any you type - comparing based on CRC8)
    support for encapusled vars or escaped chars in strings (different highlighter attrib) with error checking
    any word in PHP (but not keyword or function name) written in UpperCase highlighted as ConstantAttrib
    ActiveHighlighterSwitch - see demo (check 'Active HL' in demo app)
    parsed source code of php to get built-in function names (for php4 and php5+PECL)
    any many more.