Lightning Calendar - Organize your life — it’s about time!
HEY - Email at its best, new from Basecamp.
Google Calendar - Spend less time managing your day & more time enjoying it
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
InstAddr - Disposable email address application.