[monocasa]

A surprising number of these BASIC interpreters were ports of Microsoft BASIC so there was more consistency than you might think. That's how they made most of their money prior to buying the Quick and Dirty Operating System (QDOS) and turning around to sell it as PC-DOS 1.0.

https://en.wikipedia.org/wiki/Microsoft_BASIC

[karmakaze]

Even the Atari BASIC cartridge/ROM was supposed to be MS BASIC[0] but it didn't fit in the 8K ROM leaving any room for additional interfacing with the machine. MS BASIC was still offered separately.

I'm glad for the Atari version. Although it was less powerful, it was enough taking less space and running faster. An Integer Basic like on the Apple would have been great to have too.

https://en.wikipedia.org/wiki/Atari_Microsoft_BASIC