Just boosted this article in another post, but adding it here so I can make a few comments.
I have known about FORM for a long time, and even used it for some basic calculations. It isn’t useful for my work, really. I am just generally curious about CAS so I try things out.
But I wasn’t aware that FORM is still so widely used. Indeed, the iNSPIRE HEP database shows that Vermaseren’s FORM papers have over 3,000 citations since 1990. I assumed folks had migrated to more modern, bespoke tools.
As the article states, these papers are cited quite frequently (and there may be other ways folks reference FORM).
Now look at Vermaseren’s most cited FORM paper — “New Features of FORM” from October 2000. The 1,760 papers citing it have themselves been cited almost 86,000 times!
Clearly, this is an influential and important tool.
One that immediately comes to mind (because I use it so often) is “xAct,” a suite of Mathematica packages for working with tensors. Developed and maintained by José M. Martin-Garcia, who now works for Wolfram, and a host of volunteer collaborators (including @duetosymmetry).
xAct and it’s extensions are used by researchers in relativity, cosmology, high energy theory, and other fields.
With xAct I can do a calculation in an afternoon that would take me a week or more to do by hand. (And I am very fast.)
The website lists nearly a thousand papers and theses citing the software. Honestly, I’d guess more than twice that many have used it for published results. Some folks don’t like to admit they needed computer assistance with a calculation!
@mcnees forgot the link
https://youtu.be/N8HchXbZ_-w