Install other libraries or Ruby gems in Koala

If you haven’t already installed Sass and Compass:
gem install sass
gem install compass

Then install the library:
e.g. gem install zen-grids

For Compass project, your project should have a config.rb file. Add the require line to it:
e.g. require 'zen-grids'

Finally, add your project into Koala or reload the project.