I use thunderbird, lightning add on would add calender
http://www.mozilla.org/projects/calendar/lightning/
https://addons.mozilla.org/en-US/thu...don/lightning/
As well as open office there's
http://www.libreoffice.org/download which is more or less the same but was created when Sun was bought by Oracle, by a new team worried what Oracle may do with openoffice.