Ask HN: What do you recommend to build desktop apps?

What's your favorite SDK (or framework or toolkit) for building desktop apps?

I've got few requirements: - Cross-platform (Can build and distribute Windows, Mac, & Linux executables)

  - Great documentation

  - Open source or commercial licensing

I do Java and Ruby programming, so there a few that come to mind:

  * Swing

  * SWT

  * HotCocoa

I've also found:

  * Qt

  * wxWidgets

If you've used one of these SDKs, was it successful? Did you get the job done on time? What was the learning curve like?

Thanks