Installation info is on the install page.
1. Composition means that UI and bus. logic are separated. You add traits(logic) to UI Widgets and in 2 separate packages. First you create the UI Widget … later you make them functional by adding traits, without any logic in the UI. The widget is using passive view pastern and the trait(logic) is using presenter pastern. The result is that UI has no business logic, including in .js, the 2 are separate, making it cheaper to maintain. It’s OK if you know only one pattern and it works for you. By knowing multiple patterns/architectures you may become a more efficient developer.
2. Mobile cross platform means it targets mobile first, such as IOS Apps, IOS Safari, Android, and all others. It mostly uses HTML5 technology, including websockets, canvas, etc. (As opposed to HTML4 DOM/CSS and Ajax). Some organizations develop native IOS apps in Objective C, then write another app for IOS Safari and then another in Android. Gamina approach develops apps with half the effort/cost, using Air for IOS native and Andorid apps, and pure .js for browser/webkit.
This web site also has links to examples, support & documentation, but at this stage it’s mostly source code – this is pre version 1.0.
Name gamina comes from … because of use game-like approaches.