The company is keen to reassure its users that its e-mail products will continue to be developed.
Lotus is expected to improve collaborative working systems, such as enterprise instant messaging within Notes, and offer greater use of open standards built around Java standard J2EE and web services.
There are 110 million Lotus and Domino users worldwide but Microsoft's Outlook e-mail system and Exchange mail server have been eating into their market share.
Mike Davis, senior research analyst at Butler Group, said, "IBM's Websphere portal will give Lotus users more support, and there are many large firms that cannot change overnight. They have invested a lot in Notes in terms of training, and their Notes systems are tightly wired to others," he said.