Some of these pages are utterly useless. Others show how to do some pretty neat stuff. Many of them don't work at all, because they were abandoned halfway, or only work in one browser because that's all that mattered at the time.
If this was 1994 and I was an aoler n00b, I'd put little hardhat pictures all over the place. The message is the same: enter at your own risk, and don't bother telling me if something in this area doesn't work. It doesn't have to - that may have been the point.
All code is free to use in whatever way you choose, unless otherwise specified in the file, provided that proper attribution is made to the author, and that any changes you make are clearly documented. (I don't want your bugs to sully my good name ;)
Schroedinger's cat is dead.