[clartaq]

There have been lots of good suggestions here, but I haven't seen any discussion of using an IDE platform.

For example, [NetBeans platform](https://netbeans.org/features/platform/) provides a very high quality platform to build Swing-based applications on top of. [Eclipse](https://projects.eclipse.org/projects/eclipse.platform) offers something similar. Both of those use Java.

If you would prefer something more "lispy", you can do just about anything on top of [Emacs](https://www.gnu.org/software/emacs/) (with the possible exception of making it pretty.)

Depending on your application and familiarity with the IDE, using the base under one of these (or other) IDEs could save you tons of time.