Which PHP Framework was used to create Elgg, if any?

I asked this before, cant remember where, but it got so buried that I still do not have the answer.

I got great ideas for useful plugins but i need to learn the syntax and so forth of elgg

when i got around to really learn it, it was 1.7, but now it is 1.8 and major language syntax has been changed

thanks

Feedback and Planning

Feedback and Planning

Discussions about the past, present, and future of Elgg and this community site.