Jinja2 - Jinja2 is a template engine written in Python.
Unimus - Unimus is a Network Automation and Configuration management (NCM) solution designed for fast deployment network-wide and ease of use. Unimus does not require learning any abstraction or templating languages, and does not require any coding skills.
Jtwig - Jtwig is a configurable and extensible template engine for Java.
Oxidized - configuration backup software (IOS, JunOS) - silly attempt at rancid
mustache - Mustache is a simple web template system with implementations available for ActionScript, C++...
RANCID - RANCID - Really Awesome New Cisco confIg Differ.