GeryEngine is a template engine for PHP5. In contrary of most other PHP template engines GE is build with a Lexer and Parser which provides the template coder a much stronger language. GeryEngine is a PHP5 implementation of the well known template language Velocity written in Java. GeryEngine implements some additional functionality like inline expressions.

The inner workings of GeryEngine are as follows. First GE lexicalizes the input string to tokens. These tokens are send to the parser. The parser constructs a Abstract Syntax Tree. Then the a CodeGenerator using a Visitor Pattern walks through all branches of the AST and compiles valid PHP5 code that represents the template. Finally this code is cached and executed. The next time the template is executed it will be read from cache.