Image source, Getty Images

By James Clayton

North America technology reporter

There are so many questions about how Sam Altman was fired.

How come just four board members could act to remove the company's chief executive? Why did some board members have so little board-level experience? And why didn't Microsoft, by far the biggest investor in OpenAI, have a board seat?

The answers to those questions lie in the company's idiosyncratic structure - and to understand that you have to go back to 2015.

When OpenAI first started out, it was resolutely non-profit. Its press release made it crystal clear: "Our aim is to build value for everyone rather than shareholders," it said.

The goal was "to advance digital intelligence in the way that is most likely to benefit humanity as a whole, unconstrained by a need to generate financial return".

There was also a view that the goal of achieving artificial general intelligence (AGI) - AI that can perform any task that a human being is capable of - could be achievable with relatively little money.

In 2015, OpenAI said funders had committed $1bn (£799m) to the project - but that "we expect to only spend a tiny fraction of this in the next few years".