What can't you do in Linux?

Looks like IBM is going aggressively up against the Outlook/Exchange juggernaut. Several months ago, they made Domino, their mail server, free for any business who buys the licenses for the mail client, Notes. Now they're making Notes available for Linux. The Notes/Domino combination is more than just an email system--it's a complete database system, including calendaring, team rooms, private intranet features, addressing, and much more. While Notes is a lot different, with a fair learning curve, my clients who use it absolutely love it.
IBM unveils Lotus Notes client for Linux