Now, maybe I'm to blame here, using the nightly build of chromium, but webkit is a walking memory leak. Just for a comparison, I have the same amount of tabs on firefox and chromium and firefox is using 500mb of ram, while chromium is using 3.5 GIGABYTES. And I'm not even using it much. But really, the problem is easily reproducible. Just open whatever webkit based browser you want, and keep reloading the same moderately big page. Ram goes up, never to return. That works with a trivial program that embeds webkit via gtk, too. Or you can just look at the commits on webkit: a couple of leaks fixes every week.