I would like to compile some code on the Raspberry PI, what is the best way to do this? I'm using Arch Linux, I checked and with the pacman I can only install gcc 4.6. Do I need a cross compiler?
Cross-compilation is the process of compiling code for use on one platform on another platform. For example, you can compile software for the Raspberry Pi on a desktop (x86).
In your case, you want to compile software for the Raspberry Pi on the Raspberry Pi - this is normal. Just install
gcc and use it as you would on a normal computer. It will default to the same architecture on which it is run.
gcc is a C compiler.
g++ is a C++ compiler.