ideone.com : Ideone is an online compiler and debugging tool which allows youto compile source code and execute it online in more than 60 programming languages.
repl.it : Powerful and simple online compiler, IDE, interpreter, and REPL. Code, compile, and run code in 30+ programming languages. including JavaScript, Pytho...
TidalCycles : TidalCycles (or Tidal for short) is a language for live coding patterns.
It allows you to make musical patterns with text, describing sequences and wa...
SQL Fiddle : A tool for easy online testing and sharing of database problems and their solutions.
Cappuccino : Cappuccino is a framework which makes it easy to create advanced web apps. With just a few lines of code you can have an app built with full undo and ...