See
Idea is cool because (add your reason here):
There are also some ImprovementsNeededForIntellijIdea. -- SunnyDragon?
I believe this is proprietary code? The mitigating factor, I'm told, is that they are currently quite responsive to feature requests. -- MatthewAstley
Does IntelliJ incrementally compile code and show which methods/classes are broken? It doesn't look like it does. --ChanningWalton
I don't think it actually compiles the code, but it does do some kind of syntax analysis and highlights errors, rather like word processing spell-checkers. They've done a really nice job of making it lightweight and usable, although it doesn't cover everything yet. -- SteveFreeman
I think I'll give it a go and see how it does. What I'm really looking for is something like VisualAge for Java, but much lighter, platform independent and with a pluggable JVM. -- ChanningWalton
There's also the new EclipseIde, from the ObjectTechnologyInternational crowd. Early days, but it has some of those features and the TeamStreams version control. IdeaJ is more immediately useful, has more file-types and has (IMHO) better usability, but is not extensible. EclipseIde is more of a 'system', a tool for building tools, incremental compilation, probably more rigorous parsing, but some of the bells and whistles will be part of IBM's new workbench.
2.5 is out now. More refactorings (as well as some other things). Next version (3.0?) will allow some form of plugin support.
2.6 is out now.
I think the coolest thing about IntelliJ, at least in the early access releases, is the code inspection features. It could make static analysis and automated code review a standard part of mainstream software development.
Its actually at version 4.0 now, major changes between 3.0->4.0 is much better integration with version control systems, even more dynamic plugins (including more advanced refactoring and code inspection plugins etc) better handling of bigger multimodule project etc.
Just try it out, my development group (about 15 people) used a myriad of differnt IDE's, Emacs, JEdit, Eclipse, XCode, Forte, you name it. They all converted after trying it out, even the die hard emacs-zealots. It was pretty amazing, and it's great to have something of a company standard IDE, but I still believe it's a bad thing to force any developer to use something they havn't choosen themselves.
You may want to download a free KeyMap
See also:
What's the latest on IDEA? Is there a scaled-down free version still available for download?
No but there is an evaluation version you can download.