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GNU LibreJS 6.0.9 showing the blocked elements on the English Wikipedia main page.
GNU LibreJS 6.0.9 showing the blocked elements on the English Wikipedia main page.
Developer(s) Ruben Rodriguez, Nik Nyby
Stable release
6.0.13 / 4 May 2016; 2 years ago (2016-05-04)[1]
Repository Edit this at Wikidata
Type Browser extension
License GNU GPL v3[2]

GNU LibreJS, or simply LibreJS, is a free software web browser extension for Mozilla Firefox-based browsers, created by the GNU Project. Its purpose is to block nonfree nontrivial JavaScript programs and allow free or trivial JS in a user's web browser. The add-on was created to address the so-called "JavaScript Trap" described by Richard Stallman,[2] a situation in which many users unknowingly run proprietary software in their web browsers.[3]


GNU LibreJS aims to block nonfree JavaScript programs that are present in many websites. It is developed as part of the GNU Project by Ruben Rodriguez and Nik Nyby[2] and is included by default in the GNU IceCat browser.[4] It can also work with Tor.[5]

The add-on allows site whitelisting and has an e-mail detection system for users to contact page webmasters in order to persuade them into making their JavaScript code compliant with LibreJS.[1] According to the Free Software Foundation, many websites break while using the add-on, due to the pervasiveness of proprietary JavaScript code on the web.[6] Nevertheless, programmer and activist Richard Stallman supports the usage of GNU LibreJS.[3]

See also[edit]


  1. ^ a b "LibreJS - News". Savannah. 
  2. ^ a b c "GNU LibreJS". Retrieved 2015-07-23. 
  3. ^ a b Richard Stallman. "The JavaScript Trap". Retrieved 2015-07-23. 
  4. ^ "GNUzilla and IceCat". Free Software Foundation. 
  5. ^ n8willis (2014-12-03). "GNU LibreJS 6.0.6 released". 
  6. ^ wtheaker (2013-10-23). "LibreJS reaches version 5.4". Free Software Foundation. 

External links[edit]