Syntax highlighter : allows color display by articles of coding.
Following article: Support > Code > Posting Source Code : If you require the article of code for posting, maybe using from some Syntax Highlighter script libraries. But in case of WordPress.com, its library is ready. It’s easy. Wrapping your code by a code block. If in HTML, start : [sourcecode language=”html”], End : [/sourcecode], many languages ready. It’s free.