Useless drivel. Feel free to not read :)
Megatest has its roots in a perl script called "run_proj". It morphed in several different directions over the years and was used to drive something called "minichip" for a while. A few years ago I had started converting it into ruby but didn't complete the task and in fact can't find that code :( I also can't find the perl version although I'm sure it is in one of my lmbk backups somewhere.
Anyhow, recently I needed an automated way to run some validation of personal projects on a variety of OSes, filesystems (specifically nfs, glusterfs and afs) and architectures and wrote the current megatest pretty much from scratch over a weekend. I think it strikes a good balance between complexity of managing tests and flexibility. At least it works great for me :)