Tesseract Trainer generates a full screen, real time display of a rotating tesseract, the analogue of the cube in 4 dimensions. It also adds point textures, which give you a feel of what each of the eight faces are doing. There's a stereoscopic option which adds 3D depth to the projection from 4D. It also features music and numerous other options to play with.
Cardfile is a curses-based cardfile program compatible with the files produced by Microsoft Cardfile for Windows. It has been tested on Solaris (SysV curses), Linux (ncurses), and Mac OS X (ncurses). It includes reverse-engineered documentation and Microsoft-supplied documentation on all three CRD formats. The release is endian clean and there are no known bugs. It allows maintaining Windows address books without having to boot up Virtual PC.
blurt is Web publishing ("blogging") software. Unlike most blogging software, it does not provide you with a fancy back office, heavy duty database backends, and massive user management systems. Instead, you upload documents ("posts") in simple text format (.txt) to a directory on your Web server. blurt will figure out the rest.
Mb2md.pl not only converts mailbox files into a Maildir, but also the /var/spool/mail/$USER mailspool file. It is smart enough to not transfer a dummy message such as the one UW IMAPD puts at the start of Mbox mailboxes. You can add your own search terms to the script to make it ignore other forms of dummy first messages.