What is the difference between iCal and Vcal (the 2 calendar formats
you can export with Outlook/

Greetings!

vCalendar is the older standard, developed by the internet mail
consortium in 1996.  iCalendar is a newer and more robust version of
vCalendar, capable of transferring more information, and first was
documented in 1998.  It is based on the earlier work of of the
vCalendar specification.

The basic difference is the types of data each can transmit.  Both
handle the rudiments of time, date, place and attendees.  For more
specifics on the exact formats of each type, I refer you to the
vCalendar 1.0 specification, at:
http://www.imc.org/pdi/pdiproddev.html

and the iCaledar specification, as defined in RFC 2245:
http://www.ietf.org/rfc/rfc2445.txt

Real differences are completely implementation specific - each
implementation of the standard may include some or all of the features
listed, or may only include a subset.  Generally, you want to choose
to export whichever format your destination software will import.  For
the widest compatibility, use the vCal standard; more applications
support that, although you will loose some detail.  For maximum detail
and information, use the iCal format.

Related Information

The Calendaring Standards by Sung-Hoon Ko at Indiana University: 
(MS Word 2000 document)
http://aspen.ucs.indiana.edu/project/cctools/Calendars.doc

Googles HTML version:
http://216.239.51.100/search?q=cache:n1_opTd2J8oC:aspen.ucs.indiana.edu/project/cctools/Calendars.doc+vCalendar+iCalendar&hl=en&ie=UTF-8

Thank you for such an interesting question, and thanks to the_bursar
for the starting links!


Search Strategy:

vCalendar iCalendar
://www.google.com/search?q=vCalendar+iCalendar

iCal (or iCalendar) is laid out in <a
href="http://www.ietf.org/rfc/rfc2445.txt">rfc2445</a>, and is an
extension of vCal:<tt>
   "This memo is based on the earlier work of the vCalendar
specification
   for the exchange of personal calendaring and scheduling
information.
   In order to avoid confusion with this referenced work, this memo is
   to be known as the iCalendar specification."</tt><p>
More information on vCalendar can be found in a <a
href="http://www.imc.org/pdi/vcalwhite.html">white paper</a>, and more
general background at the <a href="http://www.imc.org/pdi/">IMC</a>,
including links to various specifications and standards.  They say:
"IMC hopes that all vCalendar developers take advantage of these new
open standards and make their software compatible with both vCalendar
1.0 and iCalendar.".