I myself use IntelliJ for my daily use. IMHO, IntelliJ beats Eclipse because: 1. Nice keyboard shortcuts-map 2. Very stable (I havent had any single crash with IntelliJ (8-9 hours non-stop). With Eclipse 3.0.1, which is much stabler than 3.0.0, I have still some minor crashes. 3. Very fast for Swing-based app. Because it is swing-based it is also nice to be run under Linux. Linux-edition of Eclipse is very slow. 4. Although there are some J2EE plugins for Eclipse (like JBOSS IDE, Lomboz or MyEclipse), J2EE support of IntelliJ is also acceptable. The J2EE supprt would be very strong when IntelliJ 5.0 comes (which incorporate Fabrique --> http://www.jetbrains.com/fabrique/ ) 5. The out-of-box syntax-coloring of IntelliJ is very nice 6. It catches every error in real time and it makes good suggestions. With Eclipse you must save save the changes first than it parse again, and very often it doesnt catch all errors 7. Although there are not so many plugins for IntelliJ, but the all plugins I have tried are very stable. Eclipse has many many plugins, which is very good because you have more options but many of them are also unstable and bad.