[Darvince]

Seeing as I don't have the $5,000 or whatever it is that Office 365 demands to buy it, nor do I want to find out how much it costs, or ever buy it, I prefer to use google docs myself and have made and shared several spreadsheets in the past with it. My only problem with it is that it's weirdly resource intensive for what it is, and for documents it becomes unusably laggy well before approaching a book-length work.