Today Mozilla released Firefox 87, introducing SmartBlock, a new feature which "intelligently fixes up web pages that are broken by our tracking protections, without compromising user privacy [...] by providing local stand-ins for blocked third-party tracking scripts. These stand-in scripts behave just enough like the original ones to make sure that the website works properly. They allow broken sites relying on the original scripts to load with their functionality intact."

As long time NoScript users may recall, this is exactly the concept behind "Script Surrogates", which I developed more than ten years ago as a NoScript "Classic" module.

In facts, in its launch post Mozilla kindly wants "to acknowledge the NoScript and uBlock Origin teams for helping to pioneer this approach.".

It's not the first time that concepts pioneered by NoScript percolate into mainstream browsers: from content blocking to XSS filters, I must admit it gets me emotional every time :)

Script Surrogates unfortunately could not be initially ported to NoScript Quantum, due to the radically different browser extensions technology it was forced into. Since then, many people using NoScript and other content blockers have been repeatedly asking for this feature to come back because it "fixed" many sites without requiring unwanted scripts (such as Google Analytics, for instance) to be enabled or ad-blocking / anti-tracking extensions to be disabled.

Script Surrogates were significantly more powerful, flexible and user-hackable than SmartBlock, and I find myself missing them in several circumstances.

I'm actually planning (i.e. trying to secure time and funds) to bring back Script Surrogates as a stand-alone extension for Firefox-based and Chromium-based browsers, both on desktop and mobile devices. This tool would complement and enhance the whole class of content blockers (including but not limited to NoScript), without requiring the specific installation of NoScript itself. Furthermore, its core functionality (on-demand script injection/replacement, native object wrapping/emulation...) would be implemented as NoScript Commons Library modules, ready to be reused by other browser extensions, like already happening with FSF's in-progress project JS-Shield.

In the meanwhile, we can all enjoy Script Surrogate's "light", mainstream young sibling, built-in in Firefox (and therefore coming soon in the Tor Browser too). Yay Mozilla!

https://hackademix.net/2021/03/23/welcome-smartblock-script-surrogates-for-the-masses/