Patterns is described as 'simple yet powerful tool for working with regular expressions. Build great patterns quickly and effortlessly with syntax coloring and with matching and replacing occurring in real time' and is an app in the Development category. There are more than 25 alternatives to Patterns for a variety of platforms, including Windows, Online / Web-based, Mac, Linux and Self-Hosted solutions. The best alternative is RegExr, which is both free and Open Source. Other great apps like Patterns are regular expressions 101 (Free), Expresso (Free), RegexBuddy (Paid) and RegexMagic (Paid).
The award-winning Expresso editor is equally suitable as a teaching tool for the beginning user of regular expressions or as a full-featured development environment for the experienced programmer or web designer with an extensive knowledge of regular expressions.
jRegExAnalyser is an interactive tool written in Java to write, test, debug, analyse and profile regular expressions. Its free and Open Source software, licensed under the terms of GPLv2 with Class Path Exception.