Web application frameworks in Smalltalk and Common Lisp
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Monday, 25th of April 2005, Vrije Universiteit Brussel
http://prog.vub.ac.be/events/2005/BADL/WebApplicationFrameworks.html

The VUB (Programming Technology Lab), ULB (deComp), Belgian Assocation
for Dynamic Languages (BADL) and the Belgian Smalltalk User Group
(BSUG) are very pleased to invite you to two presentations about web
application frameworks based on Smalltalk and Common Lisp. The two
presenters are the main authors of the respective frameworks and will
show you first-hand overviews and illustrate examples from, and
experiences with, real-world use scenarios. It will be especially
interesting to see what advantages the use of non mainstream dynamic
programming languages brings to the table in a domain that is
specifically targeted by Java and .NET frameworks. We also expect a
heated discussion about the merits of the use of continuations in
Seaside and the lack thereof in the Fractal Framework. ;)

The schedule for this event, held on Monday 25th of April, is as
follows:

- 15:00 - 16:00 Avi Bryant, Seaside
- 16:00 - 17:00 Marc Battyani, Fractal Framework
- 17:00 - 18:00 Open Podium Discussion

This event is rounded out with a little reception.

The venue for the event is the Vrije Universiteit Brussel, Campus
Etterbeek, Pleinlaan 2, 1050 Brussels, Belgium. For a description of
how to get there see http://www.vub.ac.be/english/campEt.html

The exact location is still to be determined and will be announced at
the following website:
http://prog.vub.ac.be/events/2005/BADL/WebApplicationFrameworks.html

Please make sure to register for the event at the website, so we can
plan ahead. The number of places will be limited according to the
exact location of the event, and will be announced at the website.

Below are the abstracts of the presentations and the biographies of
the speakers.


Avi Bryant, Seaside
+++++++++++++++++++

On the web, abstraction is a dirty word.  The dominant paradigms and
philosophies of web development -- CGI, Servlets, Server Pages, REST
-- provide only a thin wrapper around the low-level details of HTTP,
and encourage you to use the rough stones of the transport protocol as
the direct building blocks of your application.  Web developers by and
large reject any further abstraction in the way that assembly hackers
once rejected structured programming: it's too inflexible, uses too
many resources, and above all, it doesn't let you see what's *really*
going on.  As a result, web applications suffer the same problems now
that assembly language programs did years ago; they're fragile,
verbose, difficult to maintain and ill-suited to reuse.

That's not to say that better abstractions aren't available.  The Lisp
and Scheme communities have been working on them for years.  Paul
Graham's ViaWeb pioneered the use of closures, not query parameters,
to capture application state in each link.  Christian Quiennec showed
how to use first class continuations to invert the flow of control of
HTTP and put the server back in the driver's seat.  Macro packages
like htmlgen bring HTML into the language itself, opening up much more
than a template system can provide.  Meanwhile, object-oriented
packages like WebObjects have demonstrated how to decompose the web
page into a tree of stateful, interacting objects, allowing a finer
granularity of development.

Seaside combines these ideas and others with the rich development
environment of Smalltalk to provide a stable, complete, and innovative
web application platform.  This talk will introduce Seaside, and will
focus in particular on the ways in which these abstractions can be
leveraged to enable reuse: how to use closures, continuations, and
intelligent HTML generation to destroy the intra- and inter-page
coupling that is holding web development back.

Marc Battyani, Fractal Framework
++++++++++++++++++++++++++++++++

Web sites have evolved from static documents to simple applications
(eCommerce) and now to complete applications. Today, frameworks like
J2EE and .Net are used for writing these applications made of tens to
hundreds of object classes. These huge frameworks suffer from the
limitations of their programming languages. Other frameworks, based on
continuations, are emerging but still have limitations for complex
applications. The Framework presented here has been used in production
since 2001 and shows how the unique qualities of Common Lisp can boost
the productivity by more than an order of magnitude for writing web
applications compared to J2EE/.Net. This framework automatically
generates the presentation, modification, validation, storage and data
integrity layers of all the object classes of an application. It
provides session management, web controls and a unique way for
collaborative work. Internally, it makes extensive use of the Meta
Object Protocol, CLOS generic functions, lexical closures, and on the
fly code generation and compilation.

The speakers
++++++++++++

Avi Bryant is the co-founder of Smallthought Systems Inc.  Much of his
work centers around the use of Squeak Smalltalk as a platform for
commercial software development. As an actively contributing member of
the Squeak community, he maintains its standard version control
system, as well as packages for web development and relational and
object database access. As a consultant, he has helped companies
develop Squeak-based products for the travel, theatre, and finance
industries, higher education, and mobile devices.  Avi is based in
Vancouver, Canada but currently residing in The Netherlands.

Marc Battyani's professional activities involve electronics design and
writing software. He is the founder of Fractal Concept and the author
of several open-source libraries (mod_lisp, cl-pdf, cl-typesetting).
He works on various domains ranging from medical or industrial systems
and applications to network infrastructure management web applications
for banks as well as 3D software for robotized testing equipment, 6D
real time positioning systems for the industry and the military, smart
environmental radio sensors, etc. All the application software is
written in Common Lisp with Fractal Concept's web application
framework. Marc has a MSc in electronics and a MSc in computer science.
He lives near Fontainebleau in France.

--
Roel Wuyts                                                              
   DeComp
roel.wuyts at ulb.ac.be                               Université Libre de 
Bruxelles
http://homepages.ulb.ac.be/~rowuyts/                                    
Belgique
Vice-President of the European Smalltalk Users Group: www.esug.org