We collected some generic C++ code which we programmed over the last few years and bundled it into the so-called Audio Processing Framework (APF).
That’s the website: http://tu-berlin.de/?apf
More details (including downloads and Doxygen documentation) are here: http://dev.qu.tu-berlin.de/projects/apf/wiki
It will be presented at the Linux Audio Conference (LAC) in a few days.
Here’s the paper, feel free to cite:
Matthias Geier, Torben Hohn and Sascha Spors: “An Open Source C++ Framework for Multithreaded Realtime Multichannel Audio Applications”, Linux Audio Conference, Stanford, CA, USA, April 2012.
EDIT (July 2013): The APF now has a new home: http://AudioProcessingFramework.github.io