"Once you decide which platform you wish to access Scalix from,
you will be pleasantly surprised, because it is well supported by
both Outlook and Evolution PIM clients. For me, this provides so
much more than the usual lip service about "openness" and actually
backs up its accessibility, thanks in part because Scalix can be
used from both Windows and Linux platforms. Bundle its
accessibility with the Ajax web access and you have a groupware
suite that is both easy to use and does not dictate which browser
it works best with. Scalix is also quite extendible (yes, it's a
real word), thanks to its flexible plugins and add-ons.
"Best suited for: Larger enterprise environments, small
businesses, and non-profits with more comprehensive needs from
their groupware suite.
"Zimbra
"Do not let the fact that Zimbra is a Yahoo-owned product these
days color your judgment of what to expect from the groupware
suite. Without question, my all-time favorite Exchange alternative
as it just has a "coolness" factor that is difficult to put into
words. Perhaps some of its coolness factor can be best explained
away by talking a bit about what sets Zimbra apart from its
competition."