How do I get started with Java Development for Mac OS X?
2. Download JBuilder 3.5 Foundation from http://www.borland.com/jbuilder.
3. Visit this site and follow the directions for installing JBuilder on MacOS X:
The reason you need special instructions for setting up JBuilder on MacOS X is that Borland does not yet formally support this installation. However, you can anticipate that Borland will officially support JBuilder on MacOS X very soon after MacOS X goes golden.