features including built-in support for concurrency, and a novel type system. But one of the main

reasons that I enjoy programming in Go is that it's just plain fast. Most of my builds

when I'm programming take well under a second. Let me show you.

[whoosh!] This is the math package with implementations

of things like sine and cosine. It's over a thousand lines of Go in about twenty files,

and if we build the whole package, it builds in about 200 milliseconds.

We can also run the tests for the package, which rebuilds the package including test

functions and runs it, and that runs in well under a second.

[whoosh!] This is the whole Go package tree. There's

about a hundred and twenty thousand lines of source code and we're going to build the

whole thing. And the package tree includes flags and regular expressions and the math

library and the formatting library, an rpc package, a full parser for the Go language,

and many other packages and there: it built in under ten seconds. And that's just running

on one machine, my laptop. [whoosh!]

When builds are that fast, I can get a lot done in a day. Go is a fast, fun, and productive

language, and we hope you'll try it. There's more information and downloads available

at golang.org.