BlogLiterately (hackage): Write blog posts in Markdown format, then use BlogLiterately to do syntax highlighting, format ghci sessions, and upload to any blog supporting the metaWeblog API (such as Wordpress): http://codex.wordpress.org/XML-RPC_MetaWeblog_API.  To get started, use the provided executable BlogLiterately; see http://byorgey.wordpress.com/blogliterately/ for complete documentation.  To make further customization possible, the internals of the executable are made available as a library.  In particular, it is easy to create your own executable which adds extra custom transformations; see Text.BlogLiterately.Run.
Keywords: gpl|library|program|web