hachoir-regex is a Python library for regular expression (regex or regexp) manupulation. You can use a|b (or) and a+b (and) operators. Expressions are optimized during the construction to merge ranges, simplify repetitions, etc. It also contains a class for pattern matching, allowing you to search multiple strings and regular expressions at the same time.
libdatamatrix is an embeddable and highly extensible library made to separate data matrix (ISO/IEC16022) functionality from image reading and writing. It does error correction (instead of just error checking) and had a modular interface that allows one to extend functionality easily.
XMLSensors is a set of programs that serve as generic plugins to monitoring systems such as Nagios, Big Brother, Zabbix, and many others. The sensors output an XML status file for each sensor that is retrieved and processed by a generic plugin to the monitoring system of your choice. The XML can be published on a Web server, and transferred via network shares or SSH. It currently has 2 sensors. phpbb2_version checks the version of a phpBB forum against the offcial release, and smf_version does the same for a Simple Machines forum. There's also a dummy sensor that you can modify yourself.
Zadolbator is a simple reminder component for Jabber server. As it is installed on the server side, it can be used by all users of this Jabber server, and does not depend on the client software used. Its main purpose is to remind you about events such as birthdays or holidays, though it can be used also for keeping your everyday reminders about meetings, things to do, etc. It uses the iCalendar format to store events, so some basic understanding of iCalendar is needed to use it. This also simplifies importing existing events if they're in iCalendar format.