The Regulator is described as 'Advanced Regular expressions testing tool, featuring syntax highlighting and web-service integration with Regexlib.coms database of online regular expressions' and is an app. There are more than 25 alternatives to The Regulator for a variety of platforms, including Web-based, Windows, Mac, Linux and Self-Hosted apps. The best The Regulator alternative is RegExr, which is both free and Open Source. Other great apps like The Regulator are regular expressions 101, Expresso, RegexMate and Wildcard.