If you are on linux or OSX or setup a linux in a VM as described in the previous chapter, the simple most way to obtain NML and also ensure easy updating, is to checkout the NML repository:
hg clone http://hg.openttdcoop.org/nml nml
You then might want to make sure that nml is found in your path. The best way is to simply add that directory to your path in your ~/.profile (or ~/.bash_profile). Add a line which reads similar to
Another easy, albeit a bit hacky way is to use a symlink:
sudo ln -s `pwd`/nml/nmlc /usr/local/bin/nmlc
Whichever way, if you have thus installed nmlc, you should be able to call nmlc from whatever directory you are in and get an output which looks like
~$ nmlc --version 0.3.0.r5161:86932569ca7d from 2014-02-17 Library versions encountered: PIL: 1.1.7 PLY: 3.4
See also the more detailed NML guide for setup, including installation of required dependencies.