Mozilla has launched Mozilla Marketplace which is designed as the place where you can find web-based software that you can install on a Windows, Mac, or Linux machine just as if you were installing a desktop app.
In order to try the Marketplace you will need to install the latest Firefox 16 Nightly build in order to try the Marketplace.
Apps open in standalone Firefox browser windows. While you’re basically just using Firefox to open a website, the apps look more like native desktop apps because they don’t have all the Firefox menus around the edges.
— Tizen Experts (@TizenExperts) June 14, 2012