John Petitto published a great blog post:
Hi, I’m John Petitto, one of IBM’s Swift developers located at IBM’s Mobile Innovation Lab in Austin. We love Swift here and thought you would too so we are making our IBM Swift Sandbox available to developers on developerWorks.
The IBM Swift Sandbox is an interactive website that lets you write Swift code and execute it in a server environment – on top of Linux! Each sandbox runs on IBM Cloud in a Docker container. In addition, both the latest versions of Swift and its standard library are available for you to use.
IBM is very serious about its involvement in Apple, now open-source, language Swift. They released a sandbox where you can type in code and get it to run. Today, it has issues since alot of people are playing with it, but you can still experiment short programs for fun.