Aternative to Google Apps for Business?

You could look at Zoho: http://www.zoho.com/productivity-apps.html

That is the only alternative I know.

Thanks, but Zoho is based in the US.

They definitely have a strong US presence, but since the company grew (and is growing) out of India, and have customers globally - I'm sure there is a provision to host your account in a country/currency you're more comfortable with.

Check out Etherpad (http://etherpad.org/). It's entirely open-source, so you can host all your own files on company servers/an intranet.

Certainly not a replacement for all of Google Apps, but it's a good start.

Outlook.com with your domain could be an option. Why do you "need to" stop using them though?

Over privacy concerns, really. Some of my important clients are not confortable anymore... Outlook.com is therefore not a option.