Thanks Oxie, but I know how to install it if I wanted to. I think that I may have puzzled out where it came from now.

A while back I did a lot of playing around with streaming video for my SwallowCam project. Although we had this successfully running, I was trying to find a better (linux) method to replace the clunky old Windows server technology we were using. I did most of this on a test box, but I did run some stuff on this box, including things like Motion, gstreamer, ffmpeg etc. I suspect that Apache got involved here somewhere.

I just need to workout how to get rid of it now. I can stop it and then Xampp starts and works fine, so I'll probably just find a way to stop it running on boot.