The demise of TenFourFox is relevant: http://tenfourfox.blogspot.com/2020/04/the-end-of-tenfourfox... .
I've built Firefox on NetBSD. I wonder how many patches are required for it.
Presumably the use of rust is a dependency that needs fulfilled for building FF. Looks like there has been some work on getting rust to play with Haiku at both the Rust and Haiku ends:
https://docs.rs/haiku/0.2.0/haiku/
https://www.haiku-os.org/blog/nielx/2020-09-06_rust_on_haiku...
Some of those are for optional features like WebRTC, they are not all needed for a functional browser.
Re:Haiku OS ported and running on RISC-V
by codetrotter on Wednesday May 12, 2021 @06:15PM
(#27135810)
This thread is about fully featured browsers though. I think without WebRTC you can not call the browser fully featured.
Upstream refuses to import anything related to BSD support, so they need to be maintained out of tree.
And this is for a much more popular set of projects.
"Not an easy task" is a bit of an understatement.