uDig GIS: A First Look (Linux Journal)

Perhaps, but I question whether that mantra is actually useful. Portable languages based on VMs are thick on the ground these days; Java isn't unique in that regard. And I note that many of those languages, such as Python, Perl, Ruby, and so on, have no problem interfacing to libraries in other languages; in fact, it's one of the big selling points!

Granted, you can't deliver a byte-compiled binary as a blob to a customer this way, which is one thing that proprietary Java programs can do, but when the project is open source (like uDig), that shouldn't be a factor anyway.

If you want to deliver precompiled binaries for convenience, I think it's just fine to have one for Windows, one for MacOS X, and then let the other Unices (Linux and BSD) handle that themselves on a distribution basis.

Either way, there's no excuse for not being willing to interface with outside libraries if it would be more efficient, in programming time and in runtime performance, especially when those outside libraries are considered a standard for the field (GDAL/OGR being the "libc" of GIS).