800lb Gorilla over there sitting beside the Elephant...
...and by that I mean, Microsoft Outlook & Exchange.
Both Libre Office and Open Office are capable of handling the same general tasks as MS Office with the exception of Outlook. Other than perhaps internal communications applications specifically designed for a corporation, MS Outlook is the only communications application that does what it does out of the box.
Outlook is the new barbed wire for the digital age, fencing its users into Microsoft licensed pastures in the cloud.
Hope some of you will render my perspective obtuse by listing other product(s) that replicate Outlook & Exchange.
Biting the hand that feeds IT
