This is Go Tour, an introduction to the Go programming language.
To install the tour locally, first install Go, then run:
$ go get golang.org/x/tour/gotour
$ cd $GOPATH/bin
$ ./gotour
Unless otherwise noted, the go-tour source files are distributed
under the BSD-style license found in the LICENSE file.
Contributions should follow the same procedure as for the Go project:
http://golang.org/doc/contribute.html