Using dp.SyntaxHighlighter you can enable syntax highlighting in Community Server (CS) with just a couple of lines of code

1) Download code from http://www.dreamprojections.com/SyntaxHighlighter/ and save to ~/SyntaxHighlighter in your CS root directory

2) Enable the textarea tags to be included as content in posts update the MarkUp/Html section in the communityserver.config file to include <textarea name="true" class="true" rows="true" cols="true" />

3) Include the required JavaScript and CSS files by adding the code below to the setting: Administration > Settings > Site Content > Raw Header

4) You can find how to use the SyntaxHighlighter at   http://www.dreamprojections.com/SyntaxHighlighter/Usage.aspx