Level 23
Mozilla and the Tor Project are in the early stages of exploring the inclusion of Tor's private browsing features within the Firefox web browser in the form of a privileged extension.

This comes on the heels of a previously expressed intention of including some Tor capabilities within Firefox in the form of a Super Private Browsing mode according to Mozilla's public Research Grants 2019H1 report from May.

Since that report was made public, the results of the Mozilla Research Grants for the first half of 2019 were published, with a research grant designed to look into the "Performance and Anonymity of HTTP/2 and HTTP/3 in Tor" being awarded to University of Illinois' Nikita Borisov.

The results stemming from the research will allow both the Tor Project and Mozilla to have a closer look at the potential performance issues the integration of Tor into the Firefox browser may cause.

These are some of the issues presented by a potential Tor integration within Firefox as part of the Super Private Browsing (SPB) mode, as stated by Mozilla in its Research Grants 2019H1 report:
What alternative protocol architectures and route selection protocols would offer acceptable gains in Tor performance? And would they preserve Tor properties? Is it truly possible to deploy Tor at scale? And what would the full integration of Tor and Firefox look like?

The Tor Project followed with their own call to the research community to send in applications for Mozilla Research Grants, mentioning that the most in need of attention is Tor's network performance which also represents "one of the largest barriers to its adoption."
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