R is named partly after its initial developers, Robert Gentleman and Ross Ihaka (https://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-is-R-named...).
Erlang is named after the mathematician Erlang, but also as an abbreviation for "Ericsson Language".
https://oxfordre.com/classics/view/10.1093/acrefore/97801993...
A competing system, Judge "Haskell" Alsup, was unfortunately shot down by lawyers.