ViewFish Templating
ViewFish Templating is a PHP templating solution with the express goal of simplicity — both for use and implementation. A template can be integrated into your project in just three lines of code, and the syntax is intuitive enough that anyone comfortable with basic HTML can pick it up immediately.
Templates use a {{variable}} syntax with support for piped functions, conditional logic (isset, unless, else), loops, nested templates, default values, and caching — without requiring your template authors to learn PHP. It's powerful where it needs to be and stays out of the way everywhere else.