I think when you say "firefox os" you really mean "browser-based UI for Linux," right? You are already supposing that Linux (an actual operating system) exists

I think when you say "firefox os" you really mean "browser-based UI for Linux," right? You are already supposing that Linux (an actual operating system) exists underneath. Isn't Internet Explorer + Windows Explorer + Web Folders pretty much doing this already? Windows' Web Folders feature lets you store documents remotely and access them over HTTP from regular (non-web-enabled) applications. Internet Explorer lets you browse the local filesystem and the web from the same browser window pretty seamlessly. It seems that Firefox is indeed becoming an application deployment platform. However, it doesn't seem like a good idea to me. Instead of having one package manager in the operating system, there will be two: one system package manage and one Firefox package manager. There are all kinds of security and manageability problems with that. Already, there are many buggy Firefox plugins that cripple the browser, effectively causing a DOS attack with crashes and decreased performance. This is a good indication that we should not have confidence in Firefox's abilities to manage third party applications. Really Firefox should be in that business at all, since resource allocation and crash prevention are fundamentally operating system features. The right solution is to improve the installation experience provided by the operating system, and have it provide security-oriented integration capabilities for applications (as opposed to to the performance-oriented integration capabilities we have now). This would require the operating system to provide a sandboxed environment by default to downloaded applications. The OS needs to provide a middle ground between the almost unrestricted access given to today's downloaded applications, and the totally restricted access given to web apps; that access needs to be very close to the web app side. With this kind of severely-limited sandbox, we can then eliminate the whole UI of application installation. Instead of installation, we would just have caching. Instead of a list of programs in "Add/Remove Programs," we would just have a "Free up XXX MB of disk space" page.