One small point - I found it quite hard to read. When I first saw it I assumed it was just some type of tag cloud until I realised that the link on the left is the category.

Also any plans for having it so that I can start with a language, get a list of data-stores that can talk to my chosen language, then get a list of web-servers and so on until I've chosen my stack. Then building on this it would be great if I could get all the API's for the chosen stack!

Thanks for the great little tool!