Any hobbyist native OS in the past for classic Amigas?

[lsmart]

Well, if you ran ARP and Daves Jazzbench, you could pretty much have an alternative OS when 2.0 was still called AmigaDOS 1.4.

Of course ther was NetBSD for all MMU-Amigas with 8MB of RAM in the 90s.

[lsmart]

ARP replaced some AmigaOS1.x resources like the file requester but I don't think the goal was to get a full OS replacement. In fact, it co-existed with AmigaOS. I see it more like an enhancement for AmigaOS.

Oh, I really forgot about Arp-requesters. No I was refering to the ARP 1.3 CLI-commands. If you use their CLI-commands you have a non Commodore shell. And if you use Jazzbench you have a non Commodore Workbench. However Kickstart and all the libraries were the originals, so it really wasn´t the core of a OS, but most of the stuff the user actually sees.

[lsmart]

That sounds very interesting, do you have any links to further info?

I just popped AmigaLibDisk 228 into my SAM:

    Welcome to my Workbench replacement program!  I haven't decided on a
    name yet, but I've tentatively named it JazzBench.
   
        JazzBench (0. Copyright 1989 by David Navas
        ALL RIGHTS RESERVED.
 

For ARP see http://uk.aminet.net/misc/antiq/ARP_13.readme