Tiny PHP Forum by Ralph Capper. Sadly, TPF is no longer supported by me. At some point in the future I might re-write it and re-release as a new version. You can find some information about it on this page though.
"A ~130K PHP simple Forum. Users can create new topics and threads and reply to other threads. Database free, TinyPHPForum uses text files only. Foolproof, easy, quick, tiny. Features inc. user accounts, avatars, admin functions, emoticons, skins....."
This was a learning PHP project for me some years ago. I found that there were very few very simple, small, flat-file (database-free) forum / BBS systems out there. So I wrote this.
It was immediately popular and before long I had several people helping out with coding, design and international translations. Before I knew what had happened, the size had doubled, as had the complexity (avatars, multi-lang, multi-skin etc)
Then came the hackers. I wasn't experienced at PHP at all, let alone security, so there were holes:
By this time I was in full-time work and unable to fix what was broken. Since then people have come along and offered to help, I've added them to the developer list on SF, but not much has happened. When I look at the code now, I want to cry, as it's pretty bad.
What it needs is a serious re-write to address security concerns, make it more modular, and be able to use the existing file structure.