SQL
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Ted Codd in the early 1970s. This version, initially called "SEQUEL" ("Structured English Query Language"), was designed to manipulate and retrieve data stored in IBM's original quasi-relational database management system, System R, which a group at IBM San Jose Research Laboratory had developed during the 1970s.
SQR
In the early 80's SQR was a 'free' add-on to Gupta's SQLBase. At the time SQLBase was the only relational database that ran on IBM PCs (x86) machines. SQR was written by Israel Stern in Cleveland, probably around 1984 or 1985.