One of the main iPlanet (ex-netscape) products was email. So I'm interested to keep track of Zimbra, an open source email company. What an incredible feature set...

It just adds to my perception that no matter what segment of the established software industry you choose, there is an interesting and increasingly compelling open source alternative (or two, or three...). More proof for the fact that the software industry has changed...by leveraging the community, software companies are able to get to market faster, and at lower cost than ever. You can't unring that bell.