repl.it : Powerful and simple online compiler, IDE, interpreter, and REPL. Code, compile, and run code in 30+ programming languages. including JavaScript, Pytho...
Roam Research : A note-taking tool
for networked thought.
As easy to use as a document. As powerful as a graph database.
Roam helps you organize your research for the...
Browsershots : Browsershots makes screenshots of your web design in different operating systems and browsers. It is a free open-source online web application providi...
Babel : Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.
Ideone is an online compiler and debugging tool which allows youto compile source code and execute it online in more than 60 programming languages.