I would like to know if there is a way to compile Ruby code somehow, and
if so how?
ftp://ftp.ruby-lang.org/pub/ruby/2.1/ruby-2.1.2.tar.bz2
Wget it.
Extract it.
Run ./configure. Add flags as you need it.
Run make, then make install.
Also make sure you have stuff like libyaml installed.