My name is Giannis Sissakis and I have recently finalized some initial work on a C library for the WinAvr (AVR GCC) compiler.
It has been up to now developed using an Arduino Duemilanove board. The aim is to expand to other AVR Mega microcontrollers and to constantly add code/features.
It is hosted in google code pages and everybody can check out the code by svn or download the latest snapshot.
The link to the library at google code is http://code.google.com/p/zoavrlib/
A link to an online html documentation ishttp://www.01mech.com/sites/default/files/zoAvrLibHtml/index.html
I would very much appreciate comments/feedback wishlist requests etc.
Hope that you find this library usefull