Bug patrol and the systematic search for defects

Mistakes are part of everything we do, and bugs in the applications we build are part 
 of the development process. Methods for finding bugs are well known,
 unit testing among them. Other practices help prevent bugs in the first place. 
 This is where tools that analyze the code we've written 
 and look for parts that might cause problems come in.

Joe Walker's article 
 Bug patrol — Automate your software improvement process
 is about bugs and tools that can analyze code and catch potential problems
 early. Many of these tools can plug directly into the development environment
 and run during compilation. That's how I use the PMD plug-in in my development environment,
 which is Eclipse. Most of these tools can also run as Ant tasks,
 so you can check the entire codebase at different stages of development.