Dontpad is described as 'Dont login, just use a URL'. There are three alternatives to Dontpad, not only websites but also apps for a variety of platforms, including HP webOS, Windows, Android and Firefox. The best alternative is Pastebin.com, which is free. Other great sites and apps similar to Dontpad are WriteURL (Free) and Pastes.io (Free).
The website is mainly used by programmers to store pieces of sources code or configuration information, but anyone is more than welcome to paste any type of text. The idea behind the site is to make it more convenient for people to share large amounts of text online.