Did you know that since last Thursday we've been doing the majority of our Linux Firefox builds in Amazon? John Hopkins posted about this last week, but I wanted to highlight how important this is for Release Engineering. We can now scale up the number of Linux build machines in proportion to load. If there are no builds happening, great! Shut off the machines! If there are builds pending, we can start up more machines within minutes. Migrating to these new build systems means that we can now convert excess in-house Linux build capacity into additional Windows build capacity. Very shortly we'll be looking at running certain unit test suites in this environment as well. For all the gory details, follow along in bug 772446.