The Free Software Foundation has proposed "JavaScript License Web Labels" be added to pages to clearly mark where free and open source software is in use. In a background document, the FSF says it believes that "webmasters who use this system on their own sites will be in compliance with the relevant conditions in the GNU software licenses and many other popular free software licenses".

The labelling proposed will allow users who wish to only use free software on the web to do so easily and avoid Richard Stallman's "JavaScript Trap". Although it is possible to just disable JavaScript globally in most browsers, or selectively with tools such as NoScript, the FSF is looking for a way to be even more precise and automated.

The labels, held in a single HTML table with the id="jslicence-labels1" so that automated tools can find it quickly, will contain the name of the JavaScript file being used, the name of the licence and a link to the source code for the JavaScript file. That table should itself be present on a "labels page" which can contain its own markup around the table and which other pages on the site point to with an anchor link to the page and a rel="jslicense" attribute.

The source code for JavaScript applications has become more important since developers now routinely "minify" JavaScript code so it is quicker to download but it is much less readable. The labels are only designed to address JavaScript code that is loaded from files and not inline JavaScript. The JavaScript labels are destined to work with tools such as LibreJS, an addon to Firefox, which automatically blocks "non-free non-trivial JavaScript". Currently it does this by analysing the source code of JavaScript and blocking things with an unclear licence status, a process that would be assisted somewhat by the presence of licence labelling.

(djwm)