I've been a faithful Blackbox user since 2000. It is the perfect window manager for me. It does not waste resources in any way, being fast and light. It does not have endless dependencies. It offers everything one could wish for in a desktop environment in a minimalist way, and can be expanded with third party tools. It can be almost completely controlled via the keyboard if you wish to.
You may say that there are several window managers which fit the bill above. I agree. I tried them, and I settled on Blackbox. I guess it simply suits me best.
Sometimes I contribute small patches, although my knowledge of C++ isn't that great. My main involvement with Blackbox is maintaining the website and being there for the users on the mailing list.
You can find me on the Blackbox mailing lists, or you can reach me via the SourceForge project page for Blackbox.