Advertising Server - URL Zones / Channels?

I'm looking for any software, php-based preferred although not required, that allows you to set up zones on your web site where ads can be displayed. I'd prefer that it do this by URL, e.g. Show this ad only at the home page http://www.mysite.com/, show that ad on URLs where it is http://www.mysite.com/category1/ and the other ad on http://www.mysite.com/category2/ and so on. Ideally this will allow you to plug in code into your site where you can control what ad goes into that zone by control panel.

Most of them give you a code and that becomes the "zone" and that's all. You pop that code into your site and it shows a certain ad. The CMS that a client has is very weak and, like Wordpress, only gives you one border for every category. Joomla is pretty amazing in this respect. It allows you to have different borders for different sections on your web site. It is the same way like in these vbulletin forums. Lets say you wanted to have one type of ad in the "Hardward" section and another in the "Software" section. If you could set up your "zone" so that the ad would only appear in the url http://www.mysite.com/forum/thread.php?ch=19& for example, you'd get only that ad at that URL.

So moving that concept along, let's say I created zone "Parent channel" that would show a 468x60 banner at the URL http://www.mysite.com/parent/ then I could have advertisers set up for a certain number of impressions to appear in that zone. I could then rotate the advertisers ads easily any time I wanted by simply applying a zone for each ad, e.g. Father's Magazine would get 500 impressions in "Parent Channel" and Mother's Magazine would get 4000 impressions in the same zone, etc. I'd like to add impressions when I want via an insertion order, perhaps even have some control over when they appear (but not necessary), etc.

There are probably other ways to manage this and I'm hoping for suggestions for software and management. Thanks for all comments in advance.