What does HackerNews think of liteide?
LiteIDE is a simple, open source, cross-platform Go IDE.
Binary downloads http://sourceforge.net/projects/liteide/files
The IDE part is not true at all, why do people keep saying this? LiteIDE (aka golangide) works great, I use it all day everyday. It has syntax highlighting, autocomplete, gofmting, building, debugging, etc and is very lightweight.
Downloads: https://code.google.com/p/golangide/downloads/list Source: https://github.com/visualfc/liteide
As for the merit if REPL over something like the go playground (http://play.golang.org/) or a debugger, I can't say. Most of the code I wrote before Go was C/C++/C#/Java.
More common main page: http://code.google.com/p/liteide/ Downloads: http://code.google.com/p/golangide/downloads/list Code: https://github.com/visualfc/liteide
There were several student complaints about the lack of an IDE or debugger. These tools do exist: I use LiteIDE, with syntax highlighting, code autocomplete and built in Go debugging everyday. Perhaps the professor was not aware of LiteIDE, but his students could have used Google.
http://code.google.com/p/liteide/
https://github.com/visualfc/liteide
Go also has great built-in profiling support: http://blog.golang.org/2011/06/profiling-go-programs.html
Installing Go is easy, you can download it as an archive or use your package manager:
http://code.google.com/p/go/downloads/list
aptitude install golang-go
Also even installing Go from source is easy: cd ~/
hg clone -u release https://code.google.com/p/go
cd ~/go/src/
./all.bash
I think the hardest part is the environment variables, but these are well documented.