I just got the 100% native eclipse from Rawhide up and running. It’s using gcj4, a 100% free and open source software stack which means that it can actually be shipped with Fedora since all other viable Java platforms are non-free.
Writing a GNOME application in Java
The Eclipse RPM’s themselves are compiled natively to i386 code so it feels very snappy since there is no bytecode interpreter in place. However, gcj does provide both a bytecode compiler as well as a bytecode interpreter - it’s a full Java 1.4.2 platform. I’m using the 3.1.0 M5 RPM’s from Andrew Overholt - he told me last week at FUDCon that the CDT (C/C++ Development Tools) would hit Rawhide soon. Also check out Andrew’s Java-GNOME/Eclipse demo - it’s totally sweet (requires Flash).
GTK 2.6 provides excellent platform integration
Free Java has come a long way.