Mostly designed for Swing/SWT but the non GUI pieces work (or can be copied to work) with SWT
Get and set file types and creator codes.
Find special folders defined by the OS.
Find applications by creator code.
Find resource files in application bundles.
Open URLs in the user's favorite browser.
Handle the Apple events Open Application, Reopen Application, Quit Application, Open Document, and Print Document.
Get the name of the startup disk.
Launch applications as well as open documents, either by the application that created them or by one of your choice.
Stubbed on other non-Mac platforms
Open Source, Artistic License