other option is ArsClip http://www.joejoesoft.com/vcms/97/
but it is more of a clipboard manager application though it has permanent clip feature with variables and also hard to grasp at once.
ArsClip is great, but I haven't tried it with variables. There are many threads on DC about text expanders... some of them heated.
There does not seem to be any simple dedicated free snippet code manager with variable support out there.
You might check out Konrad Papala's Ka Type In
, which is free, but I don't know if its concept of variables matches yours, and it's getting quite old:
Ka Type In lets you define frequently used text snippets, ready to be typed into any application, document, web form. Just create a set of items, like e-mail addresses, zip code, phone number, etc. and you'll never have to type it again. The application can also auto-complete sentences, for example you can enter "Bes" and hit Ctrl+; (customizable) to expand it to "Best regards...".
In addition, you can create more sophisticated templates - with variables, which will cause a form to be shown, enabling you to setup those variables.