I was reading up awhile about non-x86 systems that came out during the early to middle 90's and failed due to lack of appications. So now I'm thinking would these platforms still be around if Linux and FOSS was as usable back then as it is now?

I'm reffering to desktops/workstations that used Windows NT, and the PowerPC machines that were supposed to have use OS/2.

Well what do you guys think?

What makes you think those architectures would have attracted F/OSS developers?

And keep in mind that Linux, as it generally exists today, is targeted at people who have broadband. Consumer broadband was available in my city in the mid 90s, but it wasn't the norm until at least the mid 2000s. So I think the 3DO would have failed back then even if it'd had an operating system like the Ouya.

I assume that you're speaking hypothetically, and you're aware that Linux was targeting x86 in those days.

Yes I'm aware of this. And by usable I mean mature and widely avaliable as it is now. One of the reasons that the MIPS and PowerPC WinNT workstations failed is that there were few appications for them.

Why were there few applications for them?

PowerPC and MIPS are still around and they run fine with Linux and *BSD. It is not unlikely that you have one or the other in your home without even knowing.
MIPS was bought not long ago by Imageon Technologies and they plan to develop it as an alternative to ARM CPUs in the mobile space, but MIPS CPUs were used all the time in settop boxes, TVs and so on.
PowerPC is still widely used in the embedded world and industrial applications, and, in form of their larger brothers, the POWER CPUs, in high performance computing.
Not to mention their usage in gaming consoles, the Playstation 1 and 2 used MIPS designs, the Playstation 3 was based on the Cell CPU, which features a PowerPC core. The XBox 360 was a pure PowerPC design. The Nintento Gamecube, Wii and Wii U are also PowerPC designs.

Sorry I should have been more clear. I'm reffering to desktop/personal computer type systems. Like the Mac clones Steve Jobs killed off when he pulled the plug.

I've already addressed that. The broadband penetration needed to make that possible wasn't there.

MIPS CPUs might get a comeback, though, since the chinese governemnt endorses MIPS as their go-to architecture for new systems. The Loongson Godson CPU is used in laptops and supercomputers in China, the Loongson laptops were even endorsed by Richard Stallman due to them being completely libre friendly.
How that works out, we will have to wait and see, but the chinese market is no small market, so MIPS on the desktop might be a thing again in the future.

I read about that a few years ago, and IIRC it them ten years to release their first CPU.They were also behind in releasing newer designs. I don't know were they are now through.

ARM might have been a better choice then MIPS.

They have the CPU already, they use it in some of their supercomputers and in some laptops. That is also why they have chosen MIPS over ARM. Until recently ARM was aimed at the embedded and small systems market, while MIPS CPUs where more general purpose, they have had a 64 bit version for years, they just scale better from very small to very large systems.

I have a MIPS netbook, a Gdium.

I was amazed to see companies make systems out of PPC and MIPS at all. To me those are more embedded CPU offerings. I used both of those a ton with real time embedded operating systems. They still might be, actually MIPS is, I don't know much about the state of PPC. But ARM really has taken over a lot of that space.

PPC used to be used in Apple computers. Hardly embedded.

Well, I don't think that Alpha would, as that got killed off in the political manoeuvrings, in the wake of the DEC collapse.

In business it's a pretty safe bet that if someone drops something of any marketable value, someone else at some point will pick it up and either use it whole or adapt it. The Alpha platform may be dead and securely buried but many of the DEC Alpha boys found a new home with AMD and they played a role in both Super7 and especially the brief Intel beater, AMD 64. I don't know what happened to their ideas or influence that AMD has slipped so far from that lofty spot, but it can never be said that DEC Alpha did not play an important role in at least CPU development. It was an amazing chip in it's time, many steps ahead of any would be competition.