> How is it different from GNU/Linux or BSDs?
I am risking the one full-time paid developer of Haiku popping up here and shouting at me, because he's done that a few times before and even written to my editor-in-chief to complain. Sadly for him, my former EIC was a hardcore techie -- it's how I met him, long before either of us worked there -- and he was on my side.
https://www.theregister.com/2023/01/11/haiku_beta_4/
Unix is a 1960s design for minicomputers. Minicomputers are text-only standalone multiuser computers. That is why things like handling serial lines (/dev/tty -- short for TeleTYpe) are buried deep in the core of Unix, but networking and graphics aren't.
There is an absolute tonne of legacy baggage like this in Unix. All Unixes, including Linux kernel 7.0. We do not use minicomputers any more; nobody even makes them. We don't have multiuser computers any more. In fact, we have multi computers per user. Modern servers are just PCs with lots of connections from other computers not from people.
In the early 1980s the Lisa flopped because it was $10K, but the Mac did well because it was $2.5K and had a GUI and no shell. The future, woo, etc.
The Mac was black and white, 1 sound channel, no hard disk, no expansion slots, and in cutting down the Lisa, Apple discarded multitasking.
Enter the Hi-Toro Lorraine. Intended to be the ultimate games console, with a powerful full-16 bit Motorola 68000 chip (a minicomputer CPU on a sdingle die) amazing colour graphics, multichannel stereo sound, but it could plug into a TV.
Commodore bought it, renamed it the Amiga, and tried to develop a fancy new ambitious OS, called Commodore Amiga Operating System: CAOS.
They couldn't get it to work so it was canned, and a replacement hastily cobbled together from the research OS Tripos written in BCPL and some new bits. It had a Mac-like windowing GUI, full preemptive multitasking (with no memory protection because the 68000 couldn't do that), and it fit on a single DD floppy (~880 kB) and into 512 kB (1/2 MB) of RAM.
It was a big hit and set a really high bar for expectations of what an inexpensive home computer could do. It ran rings around the Mac and could emulate a Mac with excellent compatibility.
A decade later a lot of people missed that. PCs and PC OSes were very boring by comparison. Sure, reliable, fairly good multitasking by then, dull grey UIs. Linux was a thing but it was for minicomputer fetishists only, and looked like it came from 20 years before Windows or Mac. (Which in a way it did.)
So a former Apple exec set up a company to make a modern geek's dream machine. Everything had true colour graphics and stereo sound now, so that was a given, not a selling point. It had to have a snazzy very fast very smooth GUI, it had to have excellent multitasking, screaming CPU performance because RISC chips were starting to take off. Mainstream computers struggled with >1 CPU so multiple RISC CPUs was the selling point, and amazing blindingly smooth multimedia support, because PCs and Macs could just about play one jerky grainy little video in a postage-stamp sized window in 267 grainy pixelated colours.
The BeBox was to be the mid-1990s geek's dream computer. Part of how they did it was an all-new multitasking single user OS with a very smooth built in GUI desktop, best-in-industry media support, built-in TCP/IP networking. All the cool bits of Windows NT, multitasking as good as Linux but pretty, a desktop better than Windows 95, and it threw all the multiuser stuff in the trash, all the boring server stuff in the trash, because FOSS OSes did that tedious business stuff.
It was beautiful.
It flopped.
The company pivoted to selling its OS on the other PowerPC kit vendor: on PowerMacs, with reverse-engineered drivers. It flopped. Classic MacOS was just barely good enough: crap multitasking, crap virtual memory, but loads of 1st class leading pro apps. BeOS had almost none.
So Be pivoted again. It ported its shiny new C++ OS to x86. You could buy multiprocessor x86 PCs in the late 1990s. I had one.
It was amazing on PC kit. It booted in under a tenth of the time that Windows sluggishly lurched into life. It could do blinding 3D like spinning solid shapes while movies played on their surfaces, and it did it all in software.
I reviewed it. I loved it.
https://archive.org/details/PersonalComputerWorldMagazine/PC...
But it still had almost no apps and while Microsoft could not prevent OEMs installing it, it could prevent them from installing a bootloader:
https://birdhouse.org/beos/byte/30-bootloader/
Be sued.
https://www.theregister.com/2002/02/20/be_inc_sues_microsoft...
It wasn't enough.
It pivoted into internet appliances but too late.
Me, I felt it should have done a deal with Acorn which was the only company with affordable multiprocessor ARM workstations at the time.
https://liam-on-linux.livejournal.com/55562.html
Haiku is an all-FOSS ground-up rewrite, but with the original desktop, which was FOSS. It's a lovely mixture of the Classic MacOS Finder and the Windows 95 Explorer, with the best bits of both but none of the bad bits.
Haiku is lovely. It's got a huge amount of Linux compatibility now. That means lots of apps, fixing the one big killer problem of BeOS.
But it is much bigger and much slower. It's still 10x smaller and 10x faster than any FOSS Unix but the original could boot in 5-10 seconds to the desktop in 1999 on a Pentium 200 from a PATA hard disk. A modern PC with an SSD should load it in half a second, but Haiku still takes 10 seconds or so. Good, sure, but not as impressive as BeOS was 25 years ago.