Long time ago I was a fan of KZ mod in CS 1.6 and I made this: http://kzplayer.azurewebsites.net. It's open source, but there is no "pipeline" to generate stuff on the fly.
You have demo player and you can explore some maps freely
You have demo player and you can explore some maps freely
It uses original file formats (dem, bsp, wad, ...), so you don't have to generate anything. You can view all current KZ world records with it here http://hlviewer.stefan100.com/