A demo is available here for fun an profit.
Have you ever tried to do some serious mathematics on IRC, ICQ, or - even worse - on MSN? If you have, then you know what I'm talking about here: It's quite hard to do so when you don't have access to some symbols like for instance greek letters or integral signs and if you can't draw fractions. You could use LaTeX-notation, but that often is no option because it's hard to read and not everyone knows LaTeX. You could also use some plugin to make the messenger render LaTeX code, but these often are hard to install or not available at all. If you're chatting with MSN, everything gets even worse since common terms like (x), (y), (a) and so on are replaced by default with a nasty icons:

This is where Formulax comes into play. Instead of writing that formula into your messenger, go to the Formulax website, give your buddy the URL and write the terms needed into the text field using LaTeX notation. You and your buddy will see the rendered formula(e) while you are typing:
The current release (1.0) is the first stable release and basically consists of a tarball of this demo page. You can download and adapt it under the terms of the GPLv3.
Formulax is authored by Mathias Weyland (that's me). I can be reached by email as well as by Jabber at hal@jabber.lugs.ch. Feedback and improvements are welcome and can be sent to me. I want to thank Tobias Rindlisbacher, Susanne Abplanalp, Andreas Gölzer, Andreas Steiger, Lumi Dox and Thierry Dussuet for their comments and testing efforts, as well as to the authors of MimeTeX and prototype since this tool relies heavely on these projects.