A few thoughts about Haiku:
(1) Haiku is not Linux-based. Haiku is built on the NewOS kernel, developed by Travis Geiselbrecht. It isn't clear to me whether Haiku depends on NewOS (which does not seem to be under active development) or whether Haiku has forked NewOS into Haiku and the Haiku team is now responsible for developing/maintaining the Haiku kernel. My guess is that Haiku is now responsible. In either case, the kernel is a niche kernel, apparently used by no one else, and it is hard to find out much about the kernel, although the source code is available for those with sufficient technical skills to evaluate the source code.
(2) Haiku's explanation about why Haiku does not base itself on Linux is (in my opinion) accurate when it comes to the Linux desktop: "Linux-based distributions stack up software – the Linux kernel, the X Window System, and various DEs with disparate toolkits such as GTK+ and Qt – that do not necessarily share the same guidelines and/or goals. This lack of consistency and overall vision manifests itself in increased complexity, insufficient integration, and inefficient solutions, making the use of your computer more complicated than it should actually be." The Linux desktop is bedeviled by upstream/downstream conflicts, as we all know from the recent issues with Budgie and the Gnome stack.
(3) Haiku uses a FreeBSD "compatibility layer" for hardware support, specifically for network and wifi adapter support. FreeBSD is a solid OS, so to the extent that the "compatibility layer" is maintained properly, that should work reliably, although that use of a "compatibility layer" seems inconsistent about Haiku's discontent with "stacking up software".
(4) Haiku appears to be heavily dependent on KDE, which can be a good thing or bad, I guess, depending on your POV about K-world, but as is the case with the FreeBSD "compatibility layer", dependence on KDE strikes me as a potential source for upstream/downstream issues.
(5) Haiku installation looks relatively difficult, at least in comparison to standard Linux installation, because Haiku seems to require self-partitioning, even for "stand alone" installations. I'm giving thought to building a stand alone "portable M.2" installation of Haiku, so I might have more to report in this respect in a few days.
(6) I've not yet been able to figure out whether and how Haiku supports modern Chromium-based browsers.
(7) I don't know if Haiku supports (or can be made to support) Flatpak.
(8) Haiku seems to have good video card support. I was initially concerned about that, because the Haiku FAQ spends a lot of electronic ink discussing VESA graphics support, which is, well, a throwback.
(9) I have a hard time wrapping my head around Haiku's "back to the 90's" design motif, so similar as it is to Windows 95/98/NT/XP motifs. I just can't figure out why Haiku has taken that approach, because it seems incompatible with gaining any sort of adoption in the current desktop market. I keep coming back to that question, like a back itch.
I'm looking forward to @[deleted]'s report on his experience. I'm intrigued by Haiku, probably because Haiku is so odd and idiosyncratic. My guess is that I'll eventually set up a "portable M.2" installation just to get Haiku out of my system.
