Intent to Implement System Add-on: about:newtab and about:home (Activity Stream)

Tim Spurway tspurway at
Mon Feb 13 14:57:40 UTC 2017

This is a notice of intent to implement the Activity Stream system add-on to supplant the current functionality on about:newtab and about:home in desktop Firefox.

Reference Links:

Meta Bug:
Tracking Project:
Engineering OKRs:
Activity Stream Dashboard:
Activity Stream Desktop Product MVP:


Activity Stream is a Firefox about:newtab and about:home replacement that aims to help users return quickly and easily to contextually relevant stuff on the web.  It is currently implemented as an Add-on SDK/Jetpack add-on, and has been running as a TestPilot experiment for some months.

Activity Stream is implemented in JS, and uses the React ( UI library.  The add-on reports UI telemetry pings back to Mozilla servers using ping-centre (  There is a brief overview of it’s architecture on our Github page (

Activity Stream has been developed using a series of A/B test based experiments, both on an opt-in Test Pilot and an opt-out production Shield audience.  Our methodology is to continue optimizing the user experience along the user engagement and user retention dimensions.  The about:newtab and about:home pages that land in Firefox will be measurably more engaging than the existing experience.


We are currently in the process of landing the Activity Stream MVP to replace about:newtab and about:home in mozilla-central.  Our target milestone is to land a fully functional MVP for Firefox 56 (by April 17, 2017)


Kate Hudson - Engineering
Dan Mosedale - Engineering
Ed Lee  - Engineering
Ursula Sarracini  - Engineering
Nan Jiang  - Engineering
Jared Kerim - Engineering
Ricky Rosario - Engineering
Marina Samuel - Data Analytics / Engineering
Heather McGaw - User Research
Bryan Bell - UX
Aaron Benson - UX
Amy Lee - UX
Jenn Chaulk - Programme Management
Nick Chapman - Product
Chris Karlof - Director

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