BIRQ stands for Balance IRQs. This is software to balance interrupts between CPUs on Linux while high load. The birq project is written in C. It has no external dependencies. Read this documentation for details about birq.
The author of birq project is Serj Kalichev <serj.kalichev(at)gmail.com>.
The project development is sponsored by "Factor-TS" company http://www.factor-ts.ru/.
The license of all birq - specific code is BSD. But note that now birq use built-in files from irqbalance project. These files were taken from Linux kernel, adapted for userspace using and use GPL licence. So now birq contain files with GPL and BSD licences. If it's important the GPL-licenced files can be replaced in future by something BSD-licenced. The GPL-licenced files implement functions for working with long bitmaps (CPU masks).