Being able to
"share" a CalenDar with someone (this always seems like a fuzzy concept to me, which includes multiple things - from letting someone see part/all of your calendar, to being able to define someone as a proxy who can Create and Accept schedule changes for you.)
Most software supports this only among people sharing a single server.
Competing with MsExchange
Some existing calendar-sharing technologies to investigate:
old NetScape (iPlanet) Calendar Server
- you can view other Yahoo calendars when making an invitation
I'd like to see someone build standalone servers and clients for this, rather than extending existing complementary products (EMail clients, PIM apps, etc.) so that people don't have to change those other apps to gain calendaring support. Likewise, make it platform-independent to maximize market: Ms Windows client support is key. Even a hosted WebApp might be OK...
There are standards in play: VCal is a format for data about an event, ICal (not the Apple software) is for the full event lifecycle transactions, but isn't final (I'm not sure how close to final it is...)
- background/setup info:
suggest meeting: initiator picks list of people to include (time for that Digital Identity directory, otherwise it slides into EMail address book); pick a day/week to consider; grab FreeBusy data from each user (need to store location for each user - FOAF/Digital Identity) (that data needs to be stored/cached somewhere that's online all the time); pick free time. Generate invitations (EMail with Attach Ment? SOAP envelope?).
- what about scheduling other resources (e.g. conference room)?
Invitee: accept or decline, send response with optional attached message (counter-propose alternate timing, etc.). Goes back only to initiator? (I could even see this waiting for v2, as email is OK for this.
- Initiator can send change to proposal, or cancel.
- Can invitees see list of other invitees? With acceptance status?
Synch to PDA. Ugh, what a nightmare, having to go platform-specific.
Aside from the technical issues, there are tricky usage issues, esp. in an increasingly networked Free Agent economy. Do you accurately block out travel time in your calendar?
In more detail: When I think about calendaring in a network economy my head explodes. Imagine you split your time between 2 different enterprises, and you might work from either of those physical sites, or from home (or Starbucks). You probably want to block off the big chunks of on-org-site time in your calendar. But if someone at one of those sites wants to schedule a meeting when you'll be onsite, how will they know which chunk of time works? And of course you might be willing to do a phone meeting from one site to the other...
put some entries in YaHoo calendar, turn on sharing
start Ms Outlook, make some dummy account (to avoid sucking in real email),
go back to YaHoo