Experience/skillsets: "SCIENCE!", but because $$$ ended up doing systems and software, mostly backend with the occasional GUI, C, C++ (have sworn off of), Perl (ditto), the various Lisps, esp. functional programming, going to look at ML next. A bit of kernel, embedded, or akin experience, e.g. a MS-DOS TSR filesystem. UNIX(TM) since 1978. Also see https://www.linkedin.com/in/haroldancell

Multics, ITS and the Lisp Machine are my ne plus ultra systems, but UNIX(TM) was good and available. I like the ITS/Lisp Machine development style, and in theory the FONC/VPRI and seL4 ones, but believe a modern web browser is a non-negotiable for users, and impractical with any of them, hence my angst.

Retired by disability, but should still be up for a few more serious projects, hence my looking at this arena which addresses many of my pain points. Anyway:

"JavaScript is utter garbage." Well, it has a lot of Scheme in it, so I'm not quite so hostile ... but I haven't use it except for a few months in 1997 ^_^. With any luck WebAssembly (https://github.com/WebAssembly) will make things a little less painful, the flip side of the "oligopoly" is only having to convince 4 organizations (Apple, Google, Microsoft, Mozilla).
To restate, the problem for the foreseeable future is the 2nd part of Postel's law, "be liberal in what you accept from others"; an objective of mine is a "desktop" that doesn't suck and has survival value, which requires a web browser that accepts, shall we say, the "best effort" of others' web pages. Or why since the early days browsers would so their best to display something in HTML without closing tags.

I believe "survival value" is very important, it's a quality of ultimate computer viri like the UNIX family that Richard Gabriel was getting at in his Worse is Better essays (https://www.dreamsongs.com/WorseIsBetter.html). A browser's ultra-complicated moving target requires creating, co-opting, or allying with a big community of developers. Hmmm, and only by doing the latter are you likely to develop fundamentally better approaches, which need buy-in from enough of the browser "oligopoly".

"Good news is many of the best [Firefox] extensions are actively maintained or should be ported in event plugin architecture changes."

That's just not going to happen per https://news.ycombinator.com/item?id=10097630 and https://news.ycombinator.com/item?id=10099240 although I suppose there's time for Mozilla to change course, but that would require their current management to get a clue or be replaced. One bottom line for me is that Servo should be a Maximum Effort instead of a "research project". There's a lot more to be said, but probably best by email if you're interested (hga@ancell-ent.com).

Me-> "starting with an Raspberry Pi seL4 port (I know, stop laughing, it's the most stable (long life promise)"

"It and Beagle port."

I seriously considered the Beagle ecosystem, but noted it's not "stable", TI makes no representation about continuing manufacture of any given board, and the earlier (and $$$) non-Bone ones don't seem to be available. But the BeagleBone Black (BBB) was a surprise smash hit (good price + very capable industrial controller SoC, e.g. can implement a 100MHz logic analyzer), so much so it had limited availability for more than a year, and now two companies are making them.

But the Raspberry Pi huge, and committed to continued manufacture of their boards, albeit with respins. And a lot cheaper, BBB $55, first gen Pis $25 and $30, new Pi 2 $40; for just messing with seL4 I bought a $25 A+. The TCB is ridiculous, albeit ideal for for OEMs, but all things considered I judged it the best for an initial learning platform. If the BBB shows staying power I'll seriously consider it.