Cruise Control, Ant and VBUnit.

"It aint pretty, but we gone and done it anyway..."

We've just got a continuous integration server set up where I work, and we have many big legacy VB6 applications that just won't go away. Your mission should you choose to accept it... is to drag this stuff into the 20th century. And I know it's now the 21st, but one step at a time huh?

http://cruisecontrol.sourceforge.net/

Cruise Control - the industry standard, I think because it 's about the only one, for Continuous Integration.

For non-java and non-.net projects, I think most of all you want to be looking at some of the original essays by the first few folks at ThoughtWorks who put it togther;

http://www.martinfowler.com/articles/continuousIntegration.html

As, of great use to us mortals who have to live in a partial non-java world, they tell you how to do it in com;

http://www.martinfowler.com/articles/ciWithCom.html

...which was the basis we (well, me, on my own one night) used to make VB6 (I know, I know, for our sins, legacy, etc etc) build from an Ant file.
Then we added in VBUnit3, and suddenly we felt a little closer to the real world.
After that worked the first time, I had to go have a lie down. Then danced round the office and made everyone come and watch... "..throw the switch egor... it's alive..."