CAMBRIDGE, Mass. (AP) _ An IBM executive who developed Lotus' popular Notes software is leaving the giant computer company to form a new software venture.

Raymond Ozzie founded Lotus in 1984 and joined International Business Machines Corp. when it bought Lotus in 1995 for $3.5 billion. He is leaving to create Rhythmix, which will develop software that can be used with Notes and Lotus' Domino web server software.

Notes is a networking software that links computers throughout a company, enabling employees to work together electronically and store files where they can easily view them.

The departure was announced Tuesday in an internal memorandum to employees from Jeff Papows, the head of IBM's Lotus unit.

IBM said it was backing Ozzie's venture but did not say how much money it is investing. The new company will be based in Massachusetts, and Ozzie said he would continue to advise Lotus.