Pict 4.1 release

We are pleased to announce a new public release of Pict, a concurrent
programming language based on the pi-calculus.

Version 4.1 is a bug-fix and portability release.  There are no
user-visible changes, but several installation problems have been
dealt with.


Pict is a language in the ML tradition, formed by adding a layer of
convenient syntactic sugar and a static type system to a tiny core.
The current release includes a Pict-to-C compiler, reference manual,
language tutorial, numerous libraries, and example programs.

The core language - an asynchronous variant of Milner, Parrow, and
Walker's pi-calculus - has been used as a theoretical foundation for a
broad class of concurrent computations. The goal in Pict is to
identify high-level idioms that arise naturally when these primitives
are used to build working programs - idioms such as basic data
structures, protocols for returning results, higher-order programming,
selective communication, and concurrent objects. The type system
integrates a number of features found in recent work on theoretical
foundations for typed object-oriented languages: higher-order
polymorphism, simple recursive types, subtyping, and a powerful
partial type inference algorithm.

Highlights of the last major release (4.0) were...
  * a complete formal definition
  * a separate compilation facility
  * an expanded set of standard libraries
  * a binary distribution for simpler installation on some common
    architectures (a full source distribution is also available)
  * numerous simplifications and generalizations from previous

The current release of the compiler is available in both source and
(for Solaris and Linux) binary form from:


For the binary distribution, go to the subdirectory labeled pict-NNN
with the largest version number NNN and retrieve the file
pict-NNN.ARCH.tar.gz for an appropriate value of ARCH. To use the
binary distribution, you will need a unix workstation with the Gnu
make utility, the Gnu C compiler, and (for some of the demos) X11.

For the source distribution, retrieve the file pict-NNN.tar.gz, with
the largest version number NNN. In addition to the tools listed above,
you will need the Objective CAML compiler, available from


        Benjamin C. Pierce (pierce@cs.indiana.edu)
        David N. Turner (dnt@an-teallach.com)