Re: enhanced diary mode?

[Alfred M. Szmidt]

Did you read the section about Calendar/Diary in the Emacs manual?

   - sending reminders via email rather than displaying them in the mode
     line;

>From (emacs)Diary Commands:

   Many users like to receive notice of events in their diary as
email.  To send such mail to yourself, use the command `M-x
diary-mail-entries'.  A prefix argument specifies how many days
(starting with today) to check; otherwise, the variable
`diary-mail-days' says how many days.

   - marking diary entries in various ways depending on the type of the
     entry (e.g.: anniversaries in red and appointment via underlining);

See (emacs)Special Diary Entries:

   Each of the standard sexp diary entries takes an optional parameter
specifying the name of a face or a single-character string to use when
marking the entry in the calendar.  Most generally, sexp diary entries
can perform arbitrary computations to determine when they apply.
*Note Sexp Diary Entries: (elisp)Sexp Diary Entries.

   - something like RefTeX's follow mode: moving cursor from one date to
     another would automatically result in displaying diary entries for
     the new date, without the need to press 'd' each time.

See calendar-move-hook:

*List of functions called whenever the cursor moves in the calendar.

For example,

  (add-hook 'calendar-move-hook (lambda () (view-diary-entries 1)))

redisplays the diary for whatever date the cursor is moved to.