irspider is a Linux-based IRC smartbot. It is very similar in functionality to a search engine on the Web. irspider goes out and spiders DCC offer bots that are in the same channel as itself, and stores tons of information on what those particular bots are offering. Users are then able to query irspider for matches against its database, or request a masslisting of everything that it knows about.
The WebGuys' Instant Message Service is a solution for small teams who need to communicate short messages more effectively than with email. It provides presence and disposition information for each user and an easy to implement protocol that can be built upon to provide more advanced features.