This depends on the cost model of the underlying resources and/or the scale you work at. For Facebook the 20% overhead of PHP of thousands and thousands of mach

This depends on the cost model of the underlying resources and/or the scale you work at. For Facebook the 20% overhead of PHP of thousands and thousands of machines is significant. On GAE where startup time is expensive, Go's quick start up time is cheap. Most languages have not been created for fast startup times. They load lots of libraries in the beginning with the assumption that the app will run on forever. That's why we went from CGI to app server in the first place. With a shared resource model and dynamic load management, this is not the case anymore.