Outlook Calendar Web Sharing

[vass0922]

I'm looking for an app that will allow me to publish many exchange 5.5 based outlook calendars to a website.
We have users that would like users in other sites (no trusts between the two, nor will there be) to be able to view their calendars in our site.

I'd rather it wasn't client based (which is why we don't want to use the outlook tool), server based is highly preferred.
I've found a few apps, some are overblown and probably more than we need (or want to pay for) and some are just junk :/

Any ideas?
I've gone through slipstick.com through all of their apps, and one or two hits but curius if anybody has any experience with it.