Expect is a tool for automating interactive applications such as telnet, ftp, passwd, fsck, rlogin, tip, etc. Expect really makes this stuff trivial. Expect is also useful for testing these same applications. And by adding Tk, you can also wrap interactive applications in X11 GUIs. Expect can make easy all sorts of tasks that are prohibitively difficult with anything else. You will find that Expect is an absolutely invaluable tool - using it, you will be able to automate tasks that you've never even thought of before - and you'll be able to do this automation quickly and easily.
Exmh is an X user interface for MH mail. MH provides a set of UNIX commands that manage folders and mail messages. MH has a zillion features as a result of several years of availability. Exmh provides a graphical interface to many of these features, as well as MIME, PGP/GPG support, NNTP, and more.
eXist is a native XML database featuring efficient, index-based XQuery processing. It provides a complete ecosystem for building applications entirely based on XML, XQuery, and related standards. The high-performance XML database engine stores textual or binary data and documents without requiring a database schema. Using XML across all layers makes mapping technologies superfluous and increases productivity. A browser-based IDE and a standardized application packaging system help developers get started quickly.
This is an example script showing how to make Netware or KixTart like login scripts with Samba. It demonstrates how to make drive mappings based upon username and/or group membership, and how to insert a user-/machinename in a BIND8 DNS server, so you can have a dynamic DNS server with which you can resolve a username/machinename to an IP address.