JsFiddle

Cloud-based JavaScript editors have become very popular in recent years, as it can be difficult tweak changes in your web applications on a local machine. With jsFiddle, it is like having a production web server at your fingertips that you can easily manipulate in real time. It also makes collaboration a breeze, as you can save a snippet and then send a link to this snippet to anyone in the world, who then in turn can fork the fiddle and edit it themselves. You can also post the snippet to a GitHub gist for collaboration there. jsFiddle further has boilerplates that you can use to get you started. This lets you link in common JavaScript frameworks. The editor has other cool features as well, such as the ability to clean up your source code. There are really no big negatives when it comes to using jsFiddle, apart from it not being a replacement for a true IDE. It also does not all the bells and whistles that newer code playgrounds have, such as CodePen, and it display advertisements, but they are not intrusive and are usually relevant to programmers.