The 64 Studio Platform Development Kit (PDK) is a version control system for GNU/Linux distributions, allowing the creation and management of many different projects, based on Debian and Ubuntu sources. PDK is written in Python, and the source code is well commented and contains documented examples.
The Advanced Linux Sound Architecture is composed of several parts. The first is a fully modularized sound driver which supports module autoloading, devfs, isapnp autoconfiguration, and gives complete access to analog audio, digital audio, control, mixer, synthesizer, DSP, MIDI, and timer components of audio hardware. It also includes a fully-featured kernel-level sequencer, a full compatibility layer for OSS/Free applications, an object-oriented C library which covers and enhances the ALSA kernel driver functionality for applications (client/server, plugins, PCM sharing/multiplexing, PCM metering, etc.), an interactive configuration program for the driver, and some simple utilities for basic management.
ABISS (Active Block I/O Scheduling System) is an extension for the Linux kernel that implements priorities for disk IO operations, and that provides a means for applications to use these priorities to obtain real-time (e.g. a guaranteed data rate) and prioritized best-effort services. The kernel code is supported by a user space daemon and a library.