Having done web servers in Java, C++, Ruby, and Python, I was pleasantly surprised by the capabilities offered by Go. In these other languages, the first thing you do is usually figure out a framework to use, which usually comes with its opinionated way of doing things. Often, the framework is really there to paper over issues with the language or the available standard libraries.

In go, the std library offers very good support, and if you need more, there are things such as gorilla (a web toolkit that enhances the std lib). There are also frameworks, of course, but many people find there is much less of a need for that.

The goroutine support is really great, and servicing concurrent client requests with them is effortless.