Scheme use

[andy@aids-unix.ARPA (Andy Cromarty)]

The computer systems group at Advanced Decision Systems (ADS) in
Mountain View, CA, is using Scheme for a variety of purposes:

 o  As a systems programming language
 o  As a vehicle for language design research
 o  As an implementation language for testbed development
 o  As a matter of moral principle

Two specific ways in which we are employing Scheme that may be of
interest are:

 o  As the implementation language for a heterogeneous distributed
    systems testbed, and correspondingly,
 
 o  As the language substrate into which we embed programming language
    constructs for distributed processing, as we design them, for study
    and use.
    
(Some of you may not know ADS.  Formerly known as Advanced Information
& Decision Systems, ADS likely has the distinction -- some would say the
"dubious distinction" -- of being the largest concentration of DoD-relevant
applied AI expertise in the world.  We also do commercial AI work.  We are
100% employee-owned, and for the most part we are engaged in contract R&D.
End of advertisement.)

Our Scheme-hacking staff includes people who learned Scheme both at MIT
in 6.001 and at Indiana under Friedman et alia, as well as designers
and implementors of other large non-Scheme LISPs.  Needless to say, this
makes for some interesting (perhaps that should read "raging") ethical
debates during group design meetings.

We currently employ four Schemes to varying extents:

 o  MIT C-Scheme, which we have retargeted for the Pyramid 90X and
    SUN-3 in addition to using it on a VAX 11/780.  (We've already
    provided the trivial SUN-3 mods to SUN, and will be shipping the
    lot of them back to MIT soon for redistribution, along with a
    package that brings MIT C-Scheme up to the RRRS standard.)

 o  Indiana's Scheme-84, which we have running on all the above
    machines, with a port to the Lisp Machine marginally in progress.
    (We also have some mods to the Scheme-84 compiler in completion
    now that bring it more in line with the RRRS standard.)

 o  MacScheme for the Apple Macintosh.  (Will, you did a nice job;
    no mods on this one yet.)

 o  A Scheme compiler/interpreter we've written ourselves and on which
    work is actively under way.  More details will follow when we feel
    we have something significant to contribute.

We also have a Butterfly processor and expect to use BBN's Scheme for
the Butterfly whenever it emerges from the cocoon, so to speak
(sorry, bad pun), and TI PC Scheme is or soon will be on order.

	cheers,				asc


p.s. I recently convinced a friend and collleague to use Scheme as
     the implementation language for a commercial dial-in system
     providing economic modeling services.  (He used TI's PC Scheme.)
     The demo was to be today; if he made the deadline, I imagine that
     must represent one of the first practical commercial uses of Scheme.