Usermin is a Web interface that can be used by any user on a UNIX system to easily perform tasks like reading mail, setting up SSH, or configuring mail forwarding. It can be thought of as a simplified version of Webmin designed for use by normal users rather than system administrators.
A modified version of the rwhod daemon as distributed by 4.3BSD once upon a time. Features include being able to send notification to a specific server (instead of broadcasting to everybody) and using network byte order for the files stored in /var/spool/rwho. It can also filter which hosts to listen to.
Minotaur is a generalized extension which lets you run Python scripts from Tcl, or Tcl from Perl, or any of the other combinations. Minotaur works by loading the appropriate shared library into another script language's context. So, for example, running Tcl from Python means that the Python main program imports the Minotaur extension, which in turn loads the Tcl libraries - thus Tcl becomes "embedded" into the Python runtime environment (which is similar to embedding Tcl in a normal C program). As involved as that sounds, performance is already surprisingly good, and the capability is turning out to be quite useful. Minotaur 0.1 is an alpha level release, meaning: it works, aside from a few quirks and bugs, but its API and implementation might still change in incompatible ways in future releases.