|    | 
     
        
      See the overview for a map of the
        history. 
        
          
          | The Actor Model by... | 
            
               ...Carl Hewitt, Henry Baker, Henry Lieberman, Will Clinger, Gul
                Agha and others while at MIT, is as foundational a model of computation
                as the Turing or Von Neumann models. It is a pure theory of object/capability
                computation and of asynchronous distributed Open
                System computation. At the Vat granularity, E
                is an Actor system. 
             | 
           
          
          | The KeyKOS Operating System by... | 
            
               ...Norm Hardy, Charley Landau,
                Bill Frantz and others while at Key Logic, is an orthogonally
                persistent pure-capability system with a B3-secure architecture.
                (B3 is the highest technical category of military security.)
                KeyKOS seems to have done everything right. Over and over, when
                we ran into hard problems, the heuristic "Do what KeyKOS
                did" was our most reliable guide to workable solutions.
               
             | 
           
          
          | The Concurrent Prolog family of languages
            by... | 
            
               ...Ehud
                "Udi" Shapiro, Jacob
                Levy, Vijay Saraswat,
                Kazunori
                Ueda, Ken Kahn, and
                many others while at the Weizmann
                Institute, Xerox
                PARC, the Fifth
                Generation Project, and several other labs. These are like
                Actors, but use Logic Variables as their synchronization &
                communications construct instead of Actor mailboxes. This has
                advantages and disadvantages. (Strangely, the "logical"
                nature of these Horn-clause logic-programming languages made no
                contribution to E.)
               
             | 
           
          
          | The Joule language by... | 
            
               ...Dean Tribble, Mark Miller, Norm Hardy and others while at
              Agorics, is E's
              most direct and important ancestor. Joule's Channels combine the
              virtues of pure Actors with those of Logic Variables. This also
              results in Promise Pipelining,
              producing a vastly more efficient use of the network and a more
              understandable and flexible way to deal with the results of asynchronous
              requests. 
             | 
           
          
          |  Original-E by... | 
            
             ...Doug Barnes, Chip Morningstar,
              Danfuzz Bornstein,
              Gordie Freedman, Eric
              Messick and others while at Communities.com
              ("Electric Communities" at the time), started by shoehorning
              Joule's elements into a Java base. For 25 years the Actor tradition
              assumed that in order to do concurrency control right, we had to
              give up sequentiality. While the invention of this deadlock-free
              alternative may have required this premise, once invented, E
              shows it coexists with sequential programming perfectly well, producing
              the first Actor language that's easy to learn.  
             | 
           
          
            | EC-Habitats | 
            
               In Original-E, Communities.com built and went into Beta with
                EC-Habitats, a graphically-rich secure system of distributed social
                virtual realities. Actual deployment demontrated the value of
                the E model,
                but also taught us many lessons.  
             | 
           
          
            | The birth of E by... | 
            
               ...Mark Miller, Bill Frantz, Jamie
              Fenton, Chip Morningstar, Doug
              Crockford, Danfuzz
              Bornstein, Bob Schumaker,
              Rob Kinnemont, Melora Svoboda and others while at Communities.com.
              E largely has
              the same goals as the Original-E, but takes these lessons into account.
              E's Promises
              are derived from Joule's Channels and from the Promise architecture
              of the Udanax system. 
             | 
           
          
            | The Open E
              Project | 
            Since spinning out of Communities.com, the currently active
              contributors to E
              include Mark Miller, Marc
              Stiegler, Tyler Close,
              Bill Frantz, Ka
              Ping Yee, Chip
              Morningstar, Jonathan
              Shapiro, Norm Hardy, E.
              Dean Tribble, Zooko (Bryce Wilcox-O'Hearn),
              Terry Stanley, Kevin
              Reid, Alan
              Karp, David
              Hopwood, Steve Jenson,
              Hal Finney, David
              Wagner, Constantine
              Plotnikov, Ken
              Kahn, Vijay Saraswat,
              Jonathan Rees, and
              Darius Bacon.(As
              a spontaneous Bazaar-style
              open-source project, this category is necessarily fuzzy. If you
              would like your name added or removed from this list, please let
              me, the webmaster-at-erights.org, know.) 
             | 
           
         
       | 
      |