Visual Assist X VS RegexPlanet Ruby

CodeRush - DevExpress CodeRush for Roslyn uses significantly less memory, works faster, and lets you start Visual Studio faster.

rubular - A ruby based regular expression editor

ReSharper C++ - ReSharper provides on-the-fly code analysis and eliminates errors in C#, VB.NET, XAML, ASP.NET, and XML

RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.

ReSharper - ReSharper is a productivity tool for visual studio that provides tools and features to help you manage your code.

RegEx Generator - RegEx Generator is a simple-to-use application that comes with the brilliance of intuitive regex and is also helping you out to test the regex.