First post, by noshutdown
basic: this was obviously dominated by micro$oft, which has a long history of basic products before the release of ibm pc. however, i am surprised that the ibm bascom(obviously rebadged from micro$oft) 1.0 wasn't released at the first moment with ibm pc, as they already have rombasic/basica provided by micro$oft.
pascal: while borland turbo pascal dominated for most of the time, micro$oft's product was much earlier, rebranded as ibm pascal and released at the first moment of ibm pc.
c: this seemd far more messy than other languages in early years of dos, probably due to lacking of standard like ansi c. lattice c released in 1982 seemed to be quite famous and was rebranded as m$c 1.0/2.0, but 3.0 and later were micro$oft's own work, and it was not until then did ibm rebrand m$c as ibm c, almost 4 years after ibm pc's release. however, i really don't know much about other c compilers in the old days.