open source DPI suggestions?

Can anyone suggest any open source DPI (deep packet inspection) projects? I am working on various telco projects in emerging markets, but can't quite justify the price for the bigger and more well known players. :/ (Until then, I'll have to rely on some of the more well known Linux and BSD traffic shaping tools) -- Also on LinkedIn?  Feel free to connect if you too are an open networker: scubacuda@gmail.com