EyeOS is a cool app that I think will take some time to find its niche. EyeOS is technically a web app, but you have to find our own web space which supports PHP if you want to use it. It attempts to be an entirely web-based OS with windows and apps and all that you can access from any web browser. Apps are easy one-click installs, but unfortunately the selection is extremely limited at this time. The bundled apps include a calendar, calculator, text editor, and web browser (how meta), and there are a few that you can install from the web including an IRC client, but that's basically it for now. However, it does look like a very slick project, so here's hoping EyeOS will find some traction (a hosted service would help) and turn out to be something worth using.