>What are prototypes and how would they be used in Squeak?

There are a number of object models.  Smalltalk has a "class-instance" 
model, which means that one creates a class (object) which has the shared 
code (methods) and meta-data (e.g. instance slot information) used to 
"create instances of the class".  You have to create a class before 
making an instance (object).

In a Prototype based OO system, objects are thought of as having both 
state (instance variables) AND behavior (methods).  When you want to 
create a 'child' of an object you can clone it and then change both its 
state and behavior without modifying its 'parent'.  Depending on the OO 
model, changes to the 'parent' may or may not show up in the 'child'.  In 
a "pure" Prototype model changes to the 'parent' do NOT show up in the 
child.  In practice one may allow a user to have either behavior as 
desired.

What is this other model good for?  It has been used to advantage in 
multimedia authoring where there are a lot of idiosyncratic objects.  
When you want to create a singleton object, why should you have to create 
a separate class?

Apple had a long-running multi-media authoring project called 'SK8' 
(pronounced 'skate') which looked at a lot of user/developers to see how 
people worked and thought about authoring.  They ended up with a very 
interesting Prototype model.  A problem with the current Squeak 
environment is that when a new user appears, he/she is essentially told 
"go learn the class libraries and then you can build something".  With 
SK8, one gets a bunch of tool pallets and can do "drag 'n drop" 
authoring.  I.e. grab and plunk down media and then "shift-click" on the 
visual elements to see/change their property sheet and add behaviors.  
There is also an "English-like" language which is fairly intuitive.

E.g.

  on MouseDown of me
    set my fillColor to Green
    play pingSound
    set my fillColor to Red
    tell CharlieRectangle to play myQuickTimeMovie
  end

  set the fillColor of every Rectangle on the Stage to mySpecialRenderer


See:
     http://sk8.research.apple.com/sk8/sk8.html
Note especially:
     http://sk8.research.apple.com/sk8/editors.html

Unfortunately, SK8 only runs on Macs.  I am certainly interested (as I 
suspect are others) in using Squeak to build a SK8-like development 
environment and Prototypes would be a big help.  Now as soon as Squeak & 
Morphics get a bit more stable..

Cheers,
-Ken