skalibs is a set of general-purpose, low-level C libraries, all in the public domain. It can replace or hide the standard C library to some extent. It is designed to allow building of small static binaries. It is used in building all skarnet.org software, including execline and s6.
execline is a very light, non-interactive scripting language, which is similar to a shell. Simple shell scripts can be easily rewritten in the execline language, improving performance and memory usage. execline was designed for use in embedded systems, but works on most Unix flavors.
Micro Tetris is based on the 1989 International Obfuscated C Code Contest Best Game entry. It is a very small implementation, with extreme similarity to the BSD Tetris implementation. So it is very suitable for small embedded systems with only serial or SSH console access. The code uses no curses or other heavy libraries, only ANSI escape sequences and the Unix "stty" command to setup and restore the display.
xstatbar is a minimal system stats viewer for X11. It shows stats for CPU usage (with support for multi-core processors), memory usage, the number of processes, battery usage, volume, and time. It displays as a small, horizontal bar that integrates nicely with tiling window managers.
mDNS Responder with Unicast runs on a server anywhere in a network and responds to mDNS queries across the network by performing a unicast DNS lookup and returning the result. Many networks use a .local top-level domain for their intranet. This has proven to be quite problematic as operating systems such as OS X have begun handling .local domains differently (in particular, prioritizing multicast DNS over conventional unicast DNS). Ideally, you'd have no problems moving away from a .local domain name, or simply not using one in the first place. That's not always possible, though. So with this tool, a lookup for "host.local" will be resolved via your existing unicast DNS servers, even if "host" does not have its own mDNS responder. Of course, the tool isn't limited to just .local domains, and can realistically work on any network where mDNS is in use.
The TI-BASIC Compiler allows you to write TI-BASIC programs for the Texas Instruments TI-83 and TI-84+ calculators using your computer instead of the calculator's keyboard. This allows you to spend more time writing code than navigating menus or trying to scroll around the tiny screen on the calculator.