[Fedora-directory-users] Calendar server

[Jeff Clowser]

John Dennis wrote:

>We are also keenly interested in a calendar server but I'll confess I'm
>confused as to the relationship you envision between FDS and calendar
>server based on caldav, could you explain?
>  
>
Well, I originally said it was somewhat off topic, and I think I'm going 
even further off with this message :)

It's not that I see caldav creating any kind of relationship between FDS 
and Calendar.  It's more along the lines that I want to deploy a FOSS 
messaging solution around FDS, based on open standards - something 
feature wise comparable to Exchange, but using non-proprietary protocols 
so that I can pick and choose clients (and everyone seems to want 
integrated mail and calendar groupware).  That requires at least a 
directory server, email server, and calendar server, implementing SMTP, 
POP, IMAP, LDAP, and something for calendar (caldav).  The one piece 
that is missing in the FOSS world is a true enterprise Calendar server 
(other than web cals...).

The Sun/Netscape calendar server is actually a pretty decent calendar 
server, but it doesn't support any protocols that there are native 
clients for.  There are some that support webdav, and caldav is close 
enough to webdav that there seems to be interest extending that support 
to caldav, which is why the Sun/Netscape cal server with caldav would 
probably be the best option.  (I know Red Hat got the Netscape Calendar 
server along with the Directory server, but the focus is on building a 
community around Directory, while Sun is supposedly opening the calendar 
(and the rest of JES) "very soon now", which is something Red Hat hasn't 
done to this point).

A lot of why calendar is missing from this puzzle is a lack of standards 
for talking to a calendar server (i.e. it's more than just calendar 
events - it's finding free busy times, discovery of resources/other cal 
users, etc).  Caldav is the closest thing to a "standard" for this 
(though I think even caldav is still evolving at this point).  Plus, 
there actually seems to be interest in developing clients to the caldav 
protocol (Mozilla Sunbird, Evolution, etc) - this is about as close as 
I've seen in the calendar world to the equivalent of POP or IMAP in the 
email world.  So, it's important that an enterprise calendar solution 
support caldav or something like it, with native clients that support it 
(the Sun Outlook plugin is not the right direction - it's still using a 
proprietary protocol, limiting you wrt native clients - not to mention 
that it's frustratingly buggy).

That said, it would be nice to see:
- FDS as the directory server (I could go with Sun DS, but FDS seems to 
have a much better community and is improving more/faster than Sun DS).
- Mail server (take your pick - there are a bunch that can integrate 
against LDAP).
- (Some offshoot of?) Sun Calendar server + caldav, hopefully resulting 
in lots of Cal clients, like we have lots of POP/IMAP clients to choose 
from.
- (Jabber/XMPP, if you want to add IM)

My (somewhat tenuous) linking of this to the topic of FDS is that 
hopefully we can break out Calendar, that someone will add caldav, and 
we can talk about integrating that against FDS :)

 - Jeff