Webu is a program that monitors web sites and RSS/Atom feeds for particular keywords, and alerts you if a particular keyword is found. It can also learn about the kind of news articles that interest you, and over time it will build up detailed knowledge about the kind of articles that you find interesting so that it can show you other articles it thinks you will like. You can also instruct the program to go and search the web for pages that it thinks you will be interested in.

Webu is completely free, has no restrictions and the Delphi source code is provided.