The vCalendar plugin provides groupware features for Claws Mail, namely:

• Receiving meeting invitations (displaying, answering, planning)
• Sending meeting invitations
• Publishing your calendar(s) and/or your free/busy status, in order to help others plan meetings
• Subscribing to public calendars
• Retrieving the free/busy status of people, to help in planning meetings
• Reminding you of events in advance

The calendars and events are displayed in a list, in the same way that Claws Mail displays your emails.

libcurl is required, http://curl.haxx.se/libcurl/

Here are a few screenshots illustrating the features:

• This is an invitation that has been sent to you. You can either accept it or decline it.
  
   
   
• Here you are inviting three people to a meeting. Marc is not available at this time, Thomas is available, and the third invitee didn't publish his free/busy information. If you hover over Marc's warning icon, or the global warning icon, you will see other times proposed, where everyone would be available.
  
   
   
• This shows vCalendar's preferences. You can choose to get reminders before your events; you can publish your full calendar, either locally or online, and publish your free/busy information. To get information from others, you can specify '%u', which is replaced by the left-hand part of the invitee's email address, and/or '%d' for the domain. Finally, after exporting your calendar or free/busy status, you can ask Claws to run a command for you; for example, a little script which would check if your PDA is plugged in and copy the data to it.
  
   
   
• This shows a public calendar from the internet, so that you can easily keep up with what happens in your area, for example.
  
   
   
• This is the popup window that will prevent you from forgetting important meetings.