Crafty is the strong chess program played on ICC. It uses all of the search algorithms you have probably read about and performs better than gnu-chess in most positions. It has a reasonable set of features to use, and offers a great starting point to try your own new search extensions.

This package contains the runtime, shared library of expat, the C library for parsing XML. Expat is a stream-oriented parser in which an application registers handlers for things the parser might find in the XML document (like start tags).

Kerberos is a system for authenticating users and services on a network. Kerberos is a trusted third-party service. That means that there is a third party (the Kerberos server) that is trusted by all the entities on the network (users and services, usually called "principals").