[linuxydave]

Well, others have written their own scripts - KusabaX springs to mind. There's another one called TinyIB or something as well.

[krapp]

I've played with Kusaba X... it's exactly the kind of software that people who hate PHP, hate PHP for.

I think you're thinking of tinyboard: https://github.com/savetheinternet/Tinyboard

[mr_vile]

http://9ch.in/overscript/ is a fairly exhaustive list