PHPContracts is a design by contract framework for the PHP programming language. It can be used in an object-oriented manner or with simple functions. Design by contract is a style of programming where classes and methods have a "contract" specified for them. If the contract is violated, then there is a defect/bug in the program.
SMPlayer is a complete media player for Windows and Linux. It uses MPlayer as a playback engine, which is capable of playing most video and audio formats (AVI, mkv, WMV, MP4, MPEG, etc.). It can also play and download YouTube videos. One of the most interesting features is that it remembers the settings of all files you play. So if you start to watch a movie but have to leave, when you open that movie again it will resume at the same point you left it, and with the same settings: audio track, subtitles, volume, etc.
Pimp is a highly interactive and programmable music player. It can be controlled with an mpd client or via a Python interpreter. Files can be played directly, and file paths are recorded in a database. Files are identified by a "fingerprint" which allows the user to identify an audio file despite file moving and tag modification. Pimp aims to be a player framework with a really small core. All features are implemented in extensions. For example, a lot of player events such as play, seek, and pause are logged in the database.
rsync is a replacement for rcp (and scp) that has many more features. It uses the "rsync algorithm" which provides a very fast method for remote files into sync. It does this by sending just the differences in the files across the link, without requiring that both sets of files are present at one of the ends of the link beforehand.