The 3DO Opera platform ran an OS called Portfolio. Developed internally at NTG/3DO by several of the same people who developed the operating system for the Amiga computer, Portfolio takes many of its design cues from Amiga. Indeed, Amiga programmers will find Portfolio quite familiar. However, Portfolio addresses many of the shortcomings leveled against Amiga, making it quite advanced for the early 1990's, particularly when compared to more popular operating systems such as MS-DOS.
Among other features, Portfolio provides:
On 2022-01-07 a snapshot of the M1 Opera's Portfolio OS from 1995-02-10 was uploaded to Archive.org by user EagleSoft. The content is mirrored here.
Find development documents here: development_documents
Things that this source could be used for:
Portfolio was ported to the M2. If you look at the 1995-02-10 dump of Portfolio you can see early work to get it to work on PowerPC.
On 2022-01-10 a snapshot of Portfolio OS v3.0 from approximately 1996-12-14 was shared by YouTuber and M2 collector Video Game Esoterica. He had acquired a collection of archives from a former M2 engineer some time ago and thought he had shared them all with other members of the 3DO community. He hadn't. After doing so it was quickly realized he had been sitting on the source code to the M2 operating system as well as numerous tools.
On 2022-01-20 EagleSoft released a slightly earlier version of the source from 1996-11-26.