What's the latest JDK?

The authoritative site for the Linux JDK is Blackdown, which is where you'd want to check this out.

However, IBM and Sun also offer JDK/JRE's for linux. Just pick one you like.

For a Java IDE you can get free personal versions of verious IDE's, like forte (Sun), jbuilder (Borland or eclipse.

Or do as I do, and use vIM