I'm using Open X and I'm really sick of it, not just the security, but I get bugs like I can't update ads because of missing plugins (it needs plugins just to run basic features). The support forums are ..well you can't even call it support.
Is DoubleClick basically the same thing? Does it have all the options like zones etc? Does it have a free version? Downsides? It's the first time I hear about this solution...