Don't know about IBM, but in case of Microsoft it was some really horrible technical decisions and a lot of internal fights that caused their downfall.

Well, maybe downfall is a harsh word for a company still very successful & profitable...

IBM is still very successful and profitable as well.

For IBM, I would definitely say that it was primarily incompetence from executives and an overwhelming level of bureaucracy/gridlock that led to its downfall. Microsoft under Steve Balmer was largely the same after Bill left.

The anti trust case had nothing to do with MS losing dominance. It is still dominant on the desktop.

- it lost the browser war because it basically disbanded the team for years

- it lost the mobile market because they tried to do Windows everywhere.

I would say the anti-trust case/ruling has certainly curtailed abusive behavior, though.

The only “abusive” behavior it curtailed was not allowing them to forbid OEMs from installing alternate operating systems - that didn’t make a difference.

Hmm...Microsoft is currently valued at close to a trillion dollars and, AFAIK, the most valuable traded company on earth.

IBM's fall happened long after the anti-trust action against them. It's Microsoft that tipped them over, not government regulators, and IBM made one disastrous mistake after another, starting with the PS/2.

While MS was convicted of anti-trust, there wasn't much of any action taken against them. The reasons for them slipping would make for an interesting book.

IBMs fall began with the PC, which they made an open design explicitly because of anti-trust pressures. They lost control of the design and the market on PCs, which led to the rise of, well, most of the market since then. Your comments are wrong enough to be attempts at revision of history.

> which they made an open design explicitly because of anti-trust pressures.

AFAIK, they didn't not, in fact, make it an “open design” intentionally. They published clear specs to encourage peripheral development, which also helped clone makers, but the BIOS was proprietary and had to be reverse engineered by clone makers to be legal. IBM sued several clone makers for infringement (largely for copying rather than reverse engineering the BIOS) and forced them to shutter, which presumably would not have happened if the design was intentionally open.

I suppose it's possible to have a difference of opinion on the meaning of "open". The BIOS was the only bit of the design that IBM had any IP in, and they definitely intended other hardware manufacturers to make compatible products, if not perhaps entire systems.

It's important to remember the regulatory environment that IBM had operated in at the time.

For more than a decade it had been illegal for IBM to exclude 3rd party hardware makers from its mainframe market, beginning with the so-called "plug compatible" peripherals, which resulted in publishing standards for the IBM Channel interface, the prohibition on refusing to allow e.g. 3rd party memory for mainframes, and importantly, the requirement that IBM license its operating systems and software to run on any manufacturer's hardware.

This was the environment that the PC was designed in. The (IMO) open design - which was not an accident - was really the only possibility that IBM had while still holding to those earlier legal restrictions on bundling, tying, and license restriction.

The fact that Compaq could reverse-engineer the BIOS was inevitable given the market opportunity. IBM tried to hold on to that thin reed but it was a doomed effort. As the "PC Compatible" market took off IBM became irrelevant to much of the growth in the industry.

> was really the only possibility that IBM had while still holding to those earlier legal restrictions on bundling, tying, and license restriction.

How does that fit in with the IBM PS/2 design, which was carefully closed?

The PS2 was released in 1987, 5 years after the US antitrust suit against IBM ended, and after IBM no longer had a monopoly position in the PC market.

It was a different era and the horses had left the barn. The PS/2 was a dead end. The original PC architecture, openly evolved, is still generating hundreds of billions in revenue each year - just not for IBM.

I'm still interested in a reference that says the IBM PC being open was a result of anti-trust.

> IBMs fall began with the PC,

IBM was enormously successful with the PC, so successful that IBM was assumed throughout the 80's that they would continue to utterly dominate the desktop market. (See the humorous 1984 Apple ad for what people thought of IBM and the PC at the time.) Everyone quaked in their boots when a new PC was imminent.

> which they made an open design explicitly because of anti-trust pressures.

I haven't heard that before in histories of the PC I've read. The way I read it was IBM made it open to cut costs and because they didn't think the PC would be a big market.

Additionally, IBM closed the design of the later PS/2 and fenced it in with patents in order to continue dominating the PC market and fend off clones, which contradicts the idea that such behavior would entice anti-trust action.

Do you have a reference for your version?