He had also heard about the IBM System R database from an article in the "IBM Research Journal" by Ed Oates. System R was also based on Codd's theories. Ellison wanted to make Oracle's product compatible with System R, but IBM stopped this by keeping the error codes for their DBMS ("DataBase Management System") secret. Ellison co-founded Oracle Corporation in 1977 with Bob Miner and Ed Oates under the name Software Development Laboratories (SDL). In 1979 SDL changed its name to Relational Software, Inc. (RSI). In 1982, RSI renamed itself Oracle Systems to make the relation to its main product, Oracle Database, clearer. At this stage Bob Miner was the company's senior programmer. In 1995, Oracle Systems Corporation changed its name to Oracle Corporation.