A quick note before bed!
I've been working on my Xpress module for Kohana (Xsetting,Xtheme,Xgrid,Xtags,Xtools and more); tonight I put together Xtags, which is a tag parsing system. The intention is to support all sorts of text formatting: from full on templating (like Smarty etc.) through simple syntax such as Markdown and BBcode (I know Kohana comes pre-packaged with Markdown in vendor tools).
So far I have packaged the Markdown PHP formatter into a proper Kohana library driver as well as semi-complete the BBcode parser.
You can see a quick demo of the 2 in action here
Hopefully tomorrow I can add a little more flesh to the bones :)