I've a command line tool I've written in some language and I like to build a web interface upon it. Can SproutCore run such a program and take the output?
I'm also taking in consideration other alternatives like Vaadin or Cappuccino (since I come from Mac development).
(I'm a software developer, I never developed for the web, and I found those 2 names googling)
Vaadin can definitely can do that.
Both SproutCore and Cappucino are browser-side frameworks for developing the UI, and have no server-side portion to run the command - so you'd probably need to use a different framework on the server too.
However : all of these frameworks seem like a huge overkill for what seems like a simple task. How complex is the user interface you wish to develop? how "interactive" is it? How much maintenance/development is it going to need?