gOS is a Linux distribution, which is often advertised as "An alternative OS with Google Apps and other Web 2.0 apps for the modern user". gOS is based on the Ubuntu distribution and a GUI largely imitative of Mac OS X Leopard.
gOS 3 Gadgets instantly launches Google Gadgets for Linux on startup, giving users access to more than 100,000 iGoogle and Google Gadgets that are small, graphically rich applications that can be added to the desktop in seconds over the Internet. gOS 3 Gadgets will also preload WINE, LXDE, and other Google software for Linux to improve the user experience.
You can download gOS here.