The IBM System/370 (S/370) is a range of computers, from entry-level to mainframes, announced as the successors to the System/360 family on June 30, 1970. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the product announcement. Like its predecessor, the System/370 became a dominant computing platform and was a major commercial success for IBM.