Anyone know of a Graphical Timeline Widget?

["Bradley F. Hartman" <hartman mcci-arl-va com>]

Hello,

Does anyone know of a configurable timeline widget?  I'm looking for something
that would graphically depict a timeline of events that conceptually 
resembles the following:

   ---------------------------------------------------------------------
  |                                                                     |
  | +Group 1                                                            |
  | |+-Task 1     ----____    ----____  ----____      ----____   ---___ |
  | |+-Task 2         ----____    ----____  ----____      ----____   -- |
  | |                                                                   |
  | +Group 2                                                            |
  | |+-Task 3     ----____    ----____  ----____      ----____   ---___ |
  | |+-Task 4         ----____    ----____  ----____      ----____   -- |
  | |                                                                   |
  | +Group 3                                                            |
  |  +-Task 5     ----____    ----____  ----____      ----____   ---___ |
  |  +-Task 6         ----____    ----____  ----____      ----____   -- |
  |                                                                     |
   ---------------------------------------------------------------------
                              Time (microseconds)

Preferably, the list of groups and tasks would be a collapsible tree.


Regards,

Brad