Recently, improving my WordPress plugin WP-SynHighlight, I chose EditArea as a source code editor with realtime syntax highlighting. The syntax of language description files for highlighting of EditArea is pretty much the same as Geshi has. So, I wrote a small converter and executed it over all Geshi files for 1.0.x version.
I have posted a patch for EditArea with all generated files.
So, now you can have EditArea with almost all power of supporting more than 130 languages 😉