MockMockWeb is a Heroku-ready Node.js-based Web application server which allows you to mock up a website in seconds. It allows you to instantly launch a website which sends an empty page (with status 200) to any request/URL and edit any page on the spot. You can also edit the layout shared throughout your website. It lets you build a mock (sometimes real) website in a request-driven interaction.
ftracer is a simple user space implementation of a Linux kernel style function tracer. It allows you to trace every call in instrumented user applications. It is useful for debugging and performance analysis due to its fine grained time stamp. This allows you to do control flow oriented debugging without any special instrumentation. So if the program does something unexpected, it's easily possible to look at the function calls before that, and use that to deduce the cause of the problem. ftracer relies on gcc generating a call on top of every function call. The tracing slows every function call down (about 3x). The tracing is per thread and does not create a global bottleneck. It supports a dump function in C, directly callable by the program or on exit, and a gdb function to dump from gdb.
Shasplit takes a large data block, splits it into smaller parts, and puts those parts into an SHA-based content-addressed store. Reassembling those parts is a trivial "cat" invocation. Repeating parts (e.g., from previous split operations) are stored only once, which allows efficient incremental backups of whole LVM snapshots via Rsync. Shasplit shows its strengths on encrypted block devices, but might be useful for non-encrypted data, too.
PASAP runs in the background, checking whether a stream exists, and, if it does, plays it. It was originally written to play back audio provided by MPD in remotely networked locations, but it also allows consumer-grade HD decoders (WDTV) to automatically play back audio/video streams from an HTTP address.