I saw that de calendar (not the calendar_plus) is not free anymore, IMHO a calendar is must in a webmail based program. I've read that there was some development to integrate a calendar into the native round cube is this so and if so is there an eta?
Grzt ;)
The calendar and calendar_plus plugins aren't developed by the core Roundcube team. Check out the kolab_calander plugin https://kolab.org/roundcubemail-plugins-kolab it full featured (other than currently lacking CalDav support) is licensed under AGPLv3 and some of the core Roundcube develops work on it.
Thanks! as there any guide how to install this in windows or is it linux only?
While I don't know of any Windows instructions I don't see why it wouldn't work on Windows.