JSFuck

JSFuck is an esoteric subset of JavaScript, where code is written using only six characters: [, ], (, ), !, and +. The name is derived from Brainfuck, an esoteric programming language that also uses a minimalistic alphabet of only punctuation. Unlike Brainfuck, which requires its own compiler or interpreter, JSFuck is valid JavaScript code, meaning that JSFuck programs can be run in any web browser or engine that interprets JavaScript. JSFuck is able to recreate all JavaScript functionality using such a limited set of characters because JavaScript allows the evaluation of any expression as any type.

== History == In July 2009, Yosuke Hasegawa created a web application called jjencode which could encode arbitrary JavaScript into an obfuscated form utilizing only the 18 symbols []()!+,\"$.:;_{}~=. In January 2010, an informal competition was held in the "Obfuscation" forum of the sla.ckers.org web application security site to come up with a way to get the minimum number of characters required down to less than eight: []()!+,/. Contributors to the thread managed to eliminate the need for the , and / characters. As of March 2010, an online encoder called JS-NoAlnum was available which utilized only the final set of six characters. By the end of 2010, Hasegawa made a new encoder available named JSF*ck which also used only the minimum six characters. In 2012, Martin Kleppe created a "jsfuck" project on GitHub, and a JSFuck.com website with a web app using that implementation of the encoder.