UberDemoTools is a program for Windows that allows you to load demos and view game statistics, chat events, obituaries and more... but most importantly, it lets you cut demos!
Just to clarify, I did not make this program, myT did!

Now supports quakelive!

If you decide to host the files too, let me know and I'll add it to the links.

Link: Get UberDemoTools!, Screenshot 1, Screenshot 2, Screenshot 3, Screenshot 4