Dear Colleagues,

If we bent our minds to it, could we produce a functional language
that was as widely used as Python?  There is reason to believe that
functional languages are particularly well suited to building web
applications.

   * Databases.  Kleisli and Mnesia (not to mention SQL and
   XQuery) have demonstrated the value of functional languages as query
   languages.

   * XML.  Xduce, Cduce, Bigwig (not to mention XSLT and XQuery)
   have demonstrated the value of functional languages for manipulating
   XML.

   * Continuations.  PLT Scheme and WASH have demonstrated the value of
   functional languages for structuring CGI interfaces.

   * Distribution.  Erlang and JoCaml have demonstrated the value of
   functional languages for distribution and mobility.

The technique of building a coalition to design, implement, and
promote a general-purpose programming language has proven
spectacularly successful for ML and Haskell.  Can we apply this
technique again, this time aimed at an application domain?

ETAPS will attract a large number of researchers to Edinburgh, and
seems an appropriate point for launching this project.  We propose
to meet on *** Wednesday 6 April 2005 in Edinburgh ***.  We hope you
can come.

The working name for this project is Links.  A quarter of a century
ago, Burstall, MacQueen, and Sannella introduced Hope, the source of
the algebraic types of ML and Haskell.  Hope was named after Hope Park
Square, located near Edinburgh University on the Meadows.  Links is
named after the Bruntsfield Links, located at the other end of the the
Meadows and site of the first public golf course.

Points to be discussed at the Links meeting include:

   * Presentations on work to date -- we hope you will contribute to this.

   * Types.  The type system of Haskell and the module system of ML
   are both extremely powerful, but quite different.  Regular expression
   types for XML are also powerful, but it is unclear how to combine
   these with polymorphism or higher-order functions.  Further, to be
   successful, any new language must play well with SOAP, Java, and C#,
   at a minimum; how do we integrate OO and FP types?

   * Effects.  It is proposed that the language be strict, with an effect
   type system (combining the advantages of Haskell monads with ML
   effects).  What variety of effects should be supported?  Can we
   provide support for laziness within this framework?    (See Wadler and
   Thiemann for relations between monads and effect type systems, see
   Wadler, Taha, and MacQueen for a proposal to support laziness in a
   strict language.)

   * Targets.  Web applications are often structures as three tiers:
   browser (running HTML, XML, Javascript, Flash, Java), server
   (running Java, C#, Python, Perl), and database (running SQL or
   XQuery).  We hope to compile code to run in all three tiers from a
   single source.  How can a compiler framework support multiple targets
   of this kind?  (See Thiemann on generating multi-tier programs from a
   single source.)

   * Organization.  How to structure the work?  Should we put in for
   European and/or US grants?

Volunteers for presentations and suggestions as to topics and
organization would be most welcome.

We look forward to hearing from you!