Vail is the next release of Windows Home Server. Aurora is a small business server based largely on the same code base as Vail. (There’s also a common framework, some kind of “client computer connector,” that extends across the two products, that is codenamed “Colorado.”)

A Community Technology Preview test build of Vail leaked to the Web earlier this year. At that time, the “Aurora” codename became known, though the actual Aurora code didn’t leak (as far as I know). In April, Microsoft released a first public beta of Vail, but didn’t deliver a public test build of Aurora.