Here in my country, Lotus Notes is still the most widely used collaborative software.
On the other hand, there are myriad of open source collaborative software out there; there are PhpGroupWare (traditional client-server), Collanos Workplace (peer to peer), Group-Office (web-based), and many others.
I wonder though; what is the best open source collaborative software to replace Lotus Notes?
(1) If an organization seek to reply its Lotus Notes with an open source collaborative version, which one do you think is the best?
(2) If one is to offer an open source collaborative software for an organization who doesn't have Lotus Notes yet, which one is the best?
Thanks,