PerlShare is a DropBox drop-in to create your own private file sharing "cloud". It consists of two parts; a client and a server. The server part lets you configure a Linux machine to accept PerlShare clients. PerlShare behaves a lot like DropBox. On collisions, for example, it creates conflicted copies. The workhorse for synchronization is Unison, a very reliable piece of software from Pascal Bach.
animbar lets you easily create your own animation on paper and transparancy. From a set of input images, two output images are computed that are printed, one on paper and one on transparency. By moving the transparency over the paper, a fascinating animation effect is created. This animation technique has been known for hundreds of years under names such as picket fence animation, barrier grid animation, and others.
TinyIB is a lightweight PHP image board which emulates the functionality of 4chan. If you use MySQL or SQLite, you can use it to create an efficient setup able to handle large amounts of traffic. If you don't use a database, it can store posts as text files for a portable setup capable of running on virtually any PHP host.
pHash is an implementation of various perceptual hashing algorithms. A perceptual hash is a fingerprint of a multimedia file derived from various features from its content. Unlike cryptographic hash functions that rely on the avalanche effect of small changes in input leading to drastic changes in the output, perceptual hashes are "close" to one another if the features are similar. Potential applications include copyright protection, similarity searches for media files, or even digital forensics.