.NET Fiddle - You will want to create an account at .NET Fiddle. You can use .NET Fiddle to create your own programs, play with concepts in this course and generally have fun! You can use your .NET Academy account to log in.

Visual Studio - Visual Studio is the premier development environment for .NET. A very full featured "Community" version is available for free and time-limited demos of more advanced versions can be downloaded. If you want to recreate the examples from this course in Visual Studio, the Community version is sufficient..