Google Adsense / Adbrite Advertising System.

Unsure if this is in the wrong section, sorry if it is.
Im looking for something similar to google adsense / adbrite.
I want to setup a website where publishers can signup and then advertisers can purchase advertising on the publishers sites (text links & banners)
Im looking to do this in a targeted niche and may expand later.
Does anyone know of good software that can manage this? Also if you have used or use software like this any reviews would be great.
Thank You

Original post by contemptx