There are Scala plug-ins available for NetBeans and Eclipse, the two most popular Java IDE's. I've tried the Scala plug-in for Eclipse, but had problems with it - strange error messages, basic things like syntax highlighting not working etc. I currently use NetBeans with the Scala plug-in for NetBeans - it works better than Eclipse, but also isn't perfect yet (auto-complete doesn't always work, and occasionally it doesn't show an error for code that doesn't compile).
IDE support will get better in the future. In a few months, Scala 2.8 will be out, and people are working on the Eclipse plug-in, so hopefully it will work better.
I've not yet worked very much with Scala but I'd recommend the Maven plugin (if you're familiar with Maven) or NetBeans for which there's and up-to-date plugin which already works quite well. I think the tool support will become generally better as Scala grows in popularity. Unfortunately I don't know about other IDEs but I think IntelliJ supports Scala, too. Don't know about Eclipse plugins for Scala.
Joined: Aug 11, 2009
Thanks. I'll give neNbeans plugin a try then.
I will get a look at the Maven plugin.
@Marco Do you have to separate Java and Scala code in Maven ?
By default the Maven plugin expects Java and Scala sources in different subdirectories (src/main/java and src/main/scala). Unfortunately I don't know if this is absolutely required. I guess it can be configured to use common directories. But as I'm new to Scala I even not sure if it's a better practice to separate the code or not.
The NetBeans Scala plugin seems to be very actively developed, so I guess we will see quickly improving tool support. I think you can't expect such plugins to be already as powerful and stable as Java support which has been improved for many years now.