There are lots of WordPress plugins for colorizing source code syntax, and many of them are pretty good.
Both are great, and it’s hard to decide which is better. Both probably have more options than common user needs. Finally, I decided to use Crayon because it has slightly better ranking in WordPress plugins directory. Here is one small sample:
Websites hosted on WordPress.com have pre-installed syntax plugin. To place source code in article on blog hosted on WordPress.com, just use [sourcecode] or just [code] tag in text view. For previous code example if your blog is on WordPress.com you, should write something like this:
More info about this feature you can find on http://en.support.wordpress.com/code/posting-source-code/