PHP advertising software --- recommendations?

Anyone here run a site with self hosted ads?

I am looking for recommendations for a PHP based advertising script/package (prefer FOSS or similar good licensing).

Anything out there others recommend?

We run a bunch of such sites. Some years ago we have tried a ton of these scripts, ended up making our own quick and dirty solution, which works for us since about 2005. Basically a 50 line php script... Spent less time coding than searching for a solution. We do not have to account for anything though, which made things rather simple.

OpenX http://www.openx.com/publisher/open-source-ad-server

Fun fact openx.com is blocked by adsblock

Francisco

OpenX recently had a big like 9 month old gaping security issue.   Very weary of it.

I use Adzerk's adOS.