Here are the tools for online collaboration

• LotusDomino.com - Lotus Notes and Domino is a proprietary, client-server collaborative groupware software and email system owned by Lotus Software, part of IBM Software.
• OSAF.biz - OSAF (Open Source Applications Foundation) is a non-profit organization developing next-generation inter-personal information management software. Our current projects include a desktop PIM application code-named "Chandler", and a server code-named "Cosmo".
• Scalix.biz - Scalix is an OSS alternative for groupware and it offers a standards-based email and calendaring platform for Linux. The software is based on HP's OpenMail technology, which Scalix has licensed and ported to Linux.
• Zimbra.info - Zimbra is another OSS alternative for groupware and is a community for building and maintaining next generation collaboration technology. Currently, this technology is available as a beta version. At Zimbra, our goal is to make e-mail, calendar, contacts and other communications technologies the best they can be. We believe that by opening the technology to the community we will insure that we can maximize innovation, scale and the ability to co-exist with existing messaging systems.
• Online-Meeting.biz - Meet online for free. In a meeting, two or more people come together, in particular to have discussions, often in a formalized way. Instead of coming together physically (in real life, face to face), also communication lines and equipment can be set up to have a discussion between people at different locations, e.g. a conference call / online meeting.

Interesting articles