PHP AiR: Analyzing PHP systems with Rascal

PHP is currently one of the most popular programming languages, widely used in both the open source community and in industry to build large web-focused applications and application frameworks. To provide a solid framework for working with large PHP systems in areas such as evaluating how language features are used, studying how PHP systems evolve, program analysis for refactoring and security validation, and software metrics, we have developed PHP AiR, a framework for PHP Analysis in Rascal. Here we briefly describe features available in PHP AiR, integration with the Eclipse PHP Development Tools, and usage scenarios in program analysis, metrics, and empirical software engineering.