RFM12 is a project mainly written in C++ and C, it's free.
RFM12 High-level API for AVR microcontrollers
High-level API for RFM12 on AVR Tomasz bla Fortuna [email protected]
Text/homepage: http://bla.thera.be/article/high-level-avr-library-for-rfm12
License: GPLv3+ If you need other license, please contact the author.