Offline application support is available in iOS 2.1 and later and in Safari 4.0 and later
So you can do offline. There is also a local database, based on SQLite, documented by Apple here – putting iOS ahead of Windows Phone 7, which has no built-in relational database for Silverlight applications. Another plus is that other WebKit-based mobile browsers should work as well, including the one in Android devices.
Integrates all aspects of a mobile web application into a single language: data modeling, user interfaces, application logic, styling and web services.
The main author is Zef Hemel, from the Delft University of Technology in the Netherlands. Mobl makes use of Stratego/XT, which is a language and toolset for program transformation, and SDF (Modular Syntax Definition Formalism), a language for defining syntax.
All rather impressive for a project that has just burst onto the scene. I installed the Eclipse add-on and enjoyed its simple license:
“This software is distributed in the hope that it will be useful.” – though I have not found time yet to try creating an application.
Update: thanks to @FransBouma for the link to the Mobl guide.