When comparing Calendar vs Informant, the Slant community recommends Calendar for most people. In the question“What are the best calendar apps for Mac OS X?” Calendar is ranked 2nd while Informant is ranked 5th.
Ranked in these QuestionsQuestion Ranking
Pro GNOME Native integration
It has online accounts integration.
Pro Currently in active development
GNOME Calendar is improved with every release cycle of GNOME.
Calendar for GNOME aims to find the perfect balance between features and usability.
Pro Integrates tasks with calendar
Informant supports integration between the user's task list with their calendar.
Pro Seamless syncing
Informant syncs seamlessly between mobile devices and PCs, so you can create an event or task anytime on your phone and it will appear on whichever computer you are using. One license includes all devices.
Pro Integrates notes with contacts, tasks and calendar
Con No support yet for WebCal
No support yet for WebCal, such as those offered by Facebook events.
A workaround exists. Since this application uses the same background services as Evolution, installing it and adding the WebCal calendars there, also adds them to GNOME Calendar.
Con Only works on GNOME
It’s too expensive.