AppCapsule is an attempt to combine WebKit, Qt, Ruby, Python, PHP, DB Technology, Web Server Technology into an application platform which will allow the construction of multi-os desktop applications using standard web languages such as HTML, CSS and JS.
The plan is to use Qt as the application container for WebKit, Web Server and Database Server.
You will need to get Qt Creator 1.3.1 for your OS
As well you will need to get and install the Qt SDK (currently 2010.02 release)