The Comedi project develops open-source drivers, tools, and libraries for data acquisition.
Comedi is a collection of drivers for a variety of common data acquisition plug-in boards. The drivers are implemented as a core Linux kernel module providing common functionality and individual low-level driver modules.
Comedilib is a user-space library that provides a developer-friendly interface to Comedi devices. Included in the Comedilib distribution is documentation, configuration and calibration utilities, and demonstration programs.
Kcomedilib is a Linux kernel module (distributed with Comedi) that provides the same interface as Comedilib in kernel space, suitable for real-time tasks. It is effectively a "kernel library" for using Comedi from real-time tasks.
(probably not accurate!)
Comedi and Comedilib are being actively developed, and because of this, new versions are sometimes buggy. However, reported bugs are usually quickly fixed.
Much of Comedi has been developed by others, suggesting the need for a contributors list.