ACM article:

https://www.sigarch.org/posit-a-potential-replacement-for-ie...

Original paper:

https://dl.acm.org/doi/10.14529/jsfi170206

Here's that paper's pdf[1]. ACM... sigh.

[1] http://www.johngustafson.net/pdfs/BeatingFloatingPoint.pdf

That paywall is symptomatic of the ACM being a professional society for computer science professors and not software practitioners. If you go to the editorial section of CACM it is frequently stuck in a loop as every decade or so there are violent ups and downs of CS program enrollment driven by the realization that “cs students are in demand” and then “IT jobs suck”, the latter of which could be addressed by having a professional society for software practitioners…

Lots of free information on posits at www.posithub.org.

That interactive diagram is nice but I don't think it should say floats only have a length. Floats as a general data format let you customize the size of the exponent field too.

As far as explaining posits, the key point I'd say to people is that a posit is almost the same as a float, but it stores the exponent in a different (variable-length) way.

Does "common" hardware support nonstandard exponent lengths for floats?

Only a few, like bfloat, but common hardware doesn't support nonstandard total lengths either.