Hi John,
You might take a look at wxWindows:
http://www.wxwindows.org/Its a C++ language, in addition to other languages including python, perl, etc, that is cross platform. PgAdmin2 was re-written into PgAdmin3 using wxWindows and it is a really nice program. It runs flawlessly under Windows, Linux, etc. WxWindows claims they make cross platform development child play.
I purchase Komodo on sale for $245.00 just a couple of days ago, so I didn't take a real close look at wxWindows.
LelandJ