Chromium has proper separation of its components (Blink, V8, Desktop, iOS, Android UIs, etc). It's "easier" for a small full-time paid team to detach the default browser UI, implement their own thing and keep the other components up to date.
Examples of this are the Electron Framework [0], Vivaldi, Brave, Opera, Yandex, Edge, etc.
Firefox instead is a nightmare to fork.
They used to have something called XulRunner[1] that allowed to create your own XUL application (things like Seamonkey, Thunderbird used it) thus making it fairly easy to fork Firefox.
After the 41 release Mozilla removed it completely. XulRunner's components were intertwined with Firefox code. Mozilla deliberately killed the easiest way to work their product.
Only light forks like Waterfox, LibreWolf are viable. Hard forks fail or struggle every single time Mozilla releases a new version (SeaMonkey, Waterfox Classic, Pale Moon, etc), lagging behind in features and performance.
Even WebKit is easier to integrate with your own UI (Safari, Gnome Web [2], etc).
Yes? I've no idea what you're implying. All the viable Chromium forks have large amounts of manpower and resources available.
The choice between forking Chromium and Firefox is mainly one of business[0]: Chrome has a >70% global marketshare, adding Edge & co even ignoring Safari it's probably around 80. Since Google also keeps pushing their own stuff, that means forking Chromium gives you much better compatibility guarantees.
[0] though the history of Chromium — and Webkit before that — forks also means there's probably a lot more knowledge floating around about maintaining such a fork, especially since Chromium itself was originally a fork (running concurrently with its source and regularly synch-ing from it, forking a dead codebase or hard-forking with no sync is a different concern)
Yeah, because of the usual open source problem: funding. Brave is funded by venture capital and crypto-crap, Vivaldi by advertising deals and Edge by the infinite coffers of Micro$oft.
Firefox forks tend to dislike associating with any of the above.
Edge, for example, is a fork maintained by Microsoft. It is a strategic project for a multi-billion company. That is not comparable to a fork of your average open-source project.
>But it's absolutely comparable to a fork of Firefox.
It's still not comparable for a fairly simple reason: the list of companies in the world that are as big as Microsoft consists of Google, and Apple, both of whom already have their own browsers.
As for why Microsoft chose Chromium, it's probably a combination of marketshare, the fact that it is a bit more cleanly architected as a result of having a decade less history than Gecko does, and the fact that they have ambitions of making a stripped down version of Electron part of the standard Windows userspace.
It was definitely a strategic business move. Chrome is eating everyone's lunch with marketshare.
Options:
1. Fork Firefox, people install Chrome anyway
2. Fork Chromium, some people realize that it's essentially the same as Chrome and don't install Chrome and just use Edge
Also, especially on mobile, Firefox is an extremely niche browser engine. The biggest browser forks in therms of global user count are actually not the likes of Edge, Brave, etc, but android Chromium forks popular in asia.
Company trying to make money off of its fork.
> Vivaldi
Company trying to ???
> Edge
Microsoft, who found that maintaining a chrome fork would be less expensive than playing catch-up with their own in-house browser.