Google dropped the invitation-only restriction for its Gmail e-mail service on Wednesday, one of its linchpin applications complementing its popular search engine.
Google launched Gmail in April 2004, and the company has been steadily integrating new features, but the service is still labeled a beta release. It includes Google Talk, an instant messaging program, and a calendar, plus other features such as spam filtering.
Gmail users previously had to pass along invitations to others so they could register for the service.
The company has positioned Gmail as a gateway to other online offerings by displaying links to its Picasa photo sharing service and Docs and Spreadsheets, a word processing and spreadsheet application.
Google has concentrated on building its infrastructure for its service-based offerings. As of Wednesday, Gmail offered users about 2.8GB of storage space for e-mail, one of the more generous limits for free services.