Collaborative workspace with a central calendar?
I am running a professional services division. I want to buy one service for online collaboration with clients. I would like a tool that supports scrum, but that has a shared calendar. Google calendar is not an option because they are a competitor. I have used Basecamp, I'm looking at Zoho, but they don't export meetings to Outlook.
I don't want an agile/scrum tool for this because I think it is a barrier to communication. I just want tasks, milestones like Basecamp, but with a shared calendar.