Tartan is a text parsing engine targeted at wiki text. The syntax specification is defined in YAML in the form of regex-based rules. It supports layering and multiple output types. Rules for Markdown to HTML are included, with optional layered extensions for tables. It is implemented in Ruby, but looking to have implementations in other languages.
JAMWiki is a Java-based Wiki engine. It features Java servlet 2.4 and Java 5+ compatibility, offers many of the features of MediaWiki, provides quick and easy setup, is integrated with the Spring Framework and Spring Security, and supports running either with or without an external database.
Zepto CMS is a tiny but flexible CMS. It has its own rights management system, which consists of groups and member structures. With these, one can control the whole site and give privileges to friends. It also uses simple version control that enables users to undo changes. It relies on modules to perform its tasks.
Instant Picture Creator is a wrapper to produce images on demand for Web sites. It has filter management, and it's possible to add new filters. It can cache filtered images, works independently (no backend is needed), and is easy to integrate with existing Web sites. It includes two basic filters for resizing images and manipulating colour palettes. Currently it supports PNG, GIF, and JPEG.
FlightFeather's goal is "social networking for everyone". This means that anyone should have a chance to run a popular social networking site on minimal hardware, and without wasting bandwidth. Whenever the system's state changes, it generates static HTML pages. Pure read operations (usually about 90% of the total) do not require the application to run at all. Since conserving computing resources translates directly into conservation of physical resources (e.g. electricity use of large server farms), such "green software" can also benefit the environment. FlightFeather is already a functional system, and runs the "bosstats.com" site.