Liquid is a template engine which was written with very specific requirements:
* It has to have beautiful and simple markup. Template engines which don't
produce good looking markup are no fun to use.
* It needs to be non evaling and secure. Liquid templates are made so that
users can edit them. You don't want to run code on your server which your
users wrote.
* It has to be stateless. Compile and render steps have to be separate so that
the expensive parsing and compiling can be done once and later on you can
just render it passing in a hash with local variables and objects.
