Well, Rust is probably well under COBOL, that's for certain.
Not in momentum, but there are tons of installations, and billions of lines of code in COBOL ever churning. If LOC was the main criterium (and not just a factor), and if COBOL projects were hosted in GitHub, most languages with be dwarfed by it.
And Groovy is semi-popular in the Java world, which is huge itself.
But as I said, TIOBE is very good in the top-10 languages, and for spotting new major contenders (by how they jump up spots).
It's not great for relative ranking of the longer tail of languages above the top-10 / top-20...
Not in momentum, but there are tons of installations, and billions of lines of code in COBOL ever churning. If LOC was the main criterium (and not just a factor), and if COBOL projects were hosted in GitHub, most languages with be dwarfed by it.
And Groovy is semi-popular in the Java world, which is huge itself.
But as I said, TIOBE is very good in the top-10 languages, and for spotting new major contenders (by how they jump up spots).
It's not great for relative ranking of the longer tail of languages above the top-10 / top-20...