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.
DMAring demonstrates a novel generic network interface card driver architecture which works in hybrid interrupt-polling mode to deliver superior real-time performance on Linux, Red Hat Linux, or Linux-RTAI-LXRT (a real-time co-kernel for Linux with user level extension). Existing Linux drivers saturate the CPU at a much lower packet rate than the maximum possible wire line packet rate, but this driver allows vanilla network cards to be used for high speed packet capturing.
GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
GeeXboX is a standalone media player Linux distribution, similar to MoviX. It's a small bootable CD that allows you to play your favorite video (DivX, XviD, H.264, MPEG 1/2, VCD, DVD, OggMedia, Windows Media, RealMedia, etc.) and audio (MP3, Audio CD, Ogg Vorbis, FLAC, MPC, etc.) files. It also supports networking, and is able to play media from Windows/Samba share, NFS, UPnP A/V Media Servers, RTP/RTSP servers, or SHOUTcast. It supports TV-out, TV tuners, DVB cards, and WiFi cards. It is based on MPlayer, and can be used on any x86, x86_64, or PowerPC computer. It's easy to modify the source to build your own GeeXboX or use an alternative boot method.
NASLite is a Network Attached Storage (NAS) server operating system designed to transform a basic computer into a dedicated file server. Utilizing highly optimized versions of Samba, uCLibc, BusyBox, and various other Linux tools, it provides SMB/CIFS, FTP, or NFS filesystem support. It accommodates multiple client OSes: Windows, Mac OS X, and Linux. NASLite offers SMART disk monitoring and large file support, and is incredibly easy to install and administer.
OKL4 Microkernels are a family of second-generation microkernels based on the original designs and implementations by Jochen Liedtke. Originally implemented in highly tuned i386-specific assembly language code, the API has seen extensive development in a number of directions, both in achieving a higher grade of platform independence and also in improving security, isolation, and robustness. There have been various re-implementations of the original binary kernel interface and its higher level successors, including L4Ka::Pistachio, L4/MIPS, and Fiasco. For this reason, the name L4 now applies to the whole microkernel family including the L4 kernel interface and its different versions.
OpenVPS is a set of software built on top of the Linux VServer aimed specifically at Web Hosting. It is not another set of kernel patches, but a set of scripts to create virtual servers, collect resource utilization information, and provide an interface to the customer as well as the administrator.
OpenWrt is a Linux distribution for wireless routers. Instead of trying to cram every possible feature into one firmware, it provides only a minimal firmware with support for add-on packages. For users, this means the ability to custom-tune features, removing unwanted packages to make room for other packages. For developers, it means being able to focus on packages without having to test and release an entire firmware.