An anonymous reader writes: I recently joined a startup, we have about 10 people altogether in various roles / responsibilities, and I handle most of the system / IT responsibilities (when I'm not in my primary role, which is software development). When trying to price licenses, I'm finding Microsoft offerings require quite a bit of upfront cost, so I'm trying the alternative solutions. LibreOffice and Google Docs work fine for the most part (we also have some MS Office users); however I'm having trouble getting a good / cheap / free solution to email, contacts, calendaring and user management in general. We have some Mac users, Windows users, need desktop clients for most of these uses as well — and there doesn't seem to be a solution that satisfies these myriad combinations. iCloud doesn't natively support non @me.com addresses (workarounds seem prone to breakage so far), Windows Live Mail doesn't support Google's CalDAV, there doesn't seem to be anything that can provide a company-wide Contacts support, etc. Ideally I can deploy a solution that has the following: Sharing calendar (or look at other people's calendar), Company-wide Contacts Address Book, Add new employee / consultants and take them offline too (in terms of user permissions, access), Clients available on Windows, OSX, possibly mobile, which support the calendaring / meeting invites / contacts list set up. Maybe I'm just out of my depths here — can Slashdot provide some direction as to what I can look at? Or is a Hosted Exchange the cheapest option? Disclaimer: I did come from a company that uses Exchange / Outlook — but the costs seem high.