Free Refill is the free REcursive FILtering Library.
It provides functionality to create recursive filters simply and hassle free.

Coding style: Google Style Guide

Setting up git hooks for development: python devtools/init-git-hooks.py

The installation requires: sudo apt-get install libeigen3-dev libgtest-dev

A manual compilation of gtest may be necessary:

cd /usr/src/gtest
sudo cmake .
sudo make
sudo mv libg* /usr/lib/

A discussion about this can be found here. In the future gtest will be shipped as part of the library following Google's advice not to install a pre-compiled copy of Google Test.

To generate documentation for this library, doxygen has to be installed. Then run the following commands:

cd doc
doxygen config.DoxyFile