Lightning Calendar - Organize your life — it’s about time!
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...
Roundcube - Web-based IMAP email client
Google Calendar - Spend less time managing your day & more time enjoying it
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.