Adsense seems to do pretty well (~$12 billion/year). It's been dropping a bit, and many individual sites don't do well with it, but some do quite well. Did you guys ever experiment with it and test the earnings? Adsense and networks like it have the benefit of showing retargeted ads, so you can get considerably better CTR's and ad inventory relevant to each individual user than you would get from just showing static IDE maker ads.

Closing down an institution like Dr. Dobb's can't be something you're doing lightly, but I cannot believe that there isn't some way to generate revenue from millions of engineers visiting your site every month. There are other tech publications that seem to do quite well.