The CDAY Calendar Almanac displays historical anniversaries such as birthdays and general events. It displays the equivalent date in multiple calendar systems, including Hebrew, Julian, JDNs, Great Underground Empire (Zork), Shire (Lord of the Rings), and Star dates. Separate GUI, command line, and Web-based versions are available, along with free libraries of thousands of events.
References for TeX and Friends is an ongoing project which provides a help file for LaTeX (and its friends like ConTeXt, Metapost, Metafont, etc.) using a state-of-the-art source format, DocBook/XML. Various output formats can be generated from the source file. Anyone can write a converter for any desired output format. Because the source file is XML, the easiest way to do this might be to use XSLT.
email@example.com is a wiki-based product catalogue and market place. This means you can add or change product descriptions, make comments on products, add points-of-sale for these products, contact other market participants, and much more. Unlike other known market places, this one is built using a wiki. In a wiki, everyone may change everything. A new wiki software has been programmed to fit the special needs of the structure of products.
Pakt is an XML abstraction layer for GObjects. It maintains a server-side tree of glib-like (Gtk, Gnome, etc) objects and provides access methods to manipulate the same (and thereby the running 'application'). Its primary use is to publish GStreamer pipelines, enabling connected clients to monitor and change the element's parameters and the pipeline's structure.