This is a companion to https://go.dev/doc/install/source providing additional instructions for various operating systems.
On OS X, a C compiler is bundled in the command line tools for Xcode, and you don't need to install the whole Xcode to compile Go. If you have already installed Xcode 4.3+, you can install command line tools from the Components tab of the Downloads preferences panel. In more recent versions of Xcode, you can use xcode-select --install command to install the command line tools without opening Xcode. To verify you have a working compiler, just invoke gcc in a freshly created Terminal window, unless you see the "gcc: command not found" error, you are ready to go.
On Ubuntu/Debian, use sudo apt-get install gcc libc6-dev. If you want to build 32-bit binaries on a 64-bit system you'll also need the libc6-dev-i386 package.
On RedHat/Centos 6, use sudo yum install gcc glibc-devel. If you want to build 32-bit binaries on a 64-bit system you'll need both glibc-devel.i386 and glibc-devel.x86_64 packages.
On Windows, install gcc with TDM-GCC. or try TDM-GCC Sourceforge link. (Make sure you add its bin subdirectory to your PATH.) Go does not support the Cygwin toolchain.