Eclipse is one of the most commonly used IDEs. It is a platform with loads of plugins. Be sure that you'll spent a lot of time configuring it. There is no way to use it effectively without understaing lots of setting options. Nothing is simple. However it is worth learning. As a developer you'd probably use it 8 hours a day so spending several hours on customisation might pay off. One yo've learned it you'd be able to create software very quickly and effectively. For me it is the best free IDE, but definetlny not the simplest. It is much better now with Eclipse Market.