OPTv2 is a template engine for PHP5 based on XML language. It focuses on portability and declarative programming, where you specify what you want to achieve, not - how it is supposed to work. Together with powerful syntax, it provides a modern, objective API designed especially for use with popular frameworks.
Currently, OPTv3 is being under development. The new version brings new design and architecture, offering an universal template compiler suitable for different types of template languages.