As pages get bigger and more complicated our general philosophy and one of the reasons it takes so long to get features in the browser is because one of our rules of thumb is that new features should not affect load time, not increase RAM and not its a strong tenet in the browser We've actully seen a significant drop in memory usage. It's always a conscern when you add new features but we try to make sure that Firefox The tough thing about memory usage is its dependnt on the environment... other software, add-ons and other things can impact performance. Everyone's mileage varies a little bit. In general we're syced about the way people are pushing Tamarind. things we didn't see on the web four or five years ago. Firefox 4 will use tamarind. The alpha's you're looking at represent almost two years of development with major performance enhancements. We've got more people dedicated to mac than windows right now. there's a big interest improving . The mac is a big focus. We've got three full time. There's differently room for improvement in terms of the look and feel i can't promise but maybe firefox 3. 1600 people contributed to the release of Firefox 2. The UI is well controlled by a smaller group of experts who make decisions about UI and feature improvements. You don't build a great UI by concensuse. the beauty of open source is that its open to what people want.Seamonkey demostrates that some people actually like the integrated approach. If someone has a better idea and they can go off and run with it and if the idea is successful they will find and audience. Everyone we talk to How do we find features that hit the 90% use case. If its a smaller set of people than that. WE're looking for the features that help everyone and if you want something richer that that you can download an extension.