Some Smalltalk based open-source projects
AIDA/Web is a Smalltalk web application framework for building complex web applications.

More info: www.aidaweb.si
tODE is a Smalltalk development environment written in Seaside application that runs in Pharo and GemStone

More info: tODE Forum
Dale's Blog
Magma is a multi-user Object Database.

More info: wiki.squeak.org/squeak/2665
Magritte is a meta-description framework.
Pier is a Content Management System.
More info: www.lukas-renggli.ch/smalltalk/magritte, www.piercms.com
Moose is a platform for software analysis with tools like Mondrian, Glamour ...

More info: www.moosetechnology.org
Seaside provides a layered set of abstractions over HTTP and HTML that let you build highly interactive web applications quickly, reusably and maintainably.
More info: www.seaside.st Tutorial: seaside.gemstone.com
Iliad is a Smalltalk web application framework. It is designed to be simple and make web development as effective as possible.

More info: www.iliadproject.org
Smalltalk web server.
More info: www.swazoo.org
OpenCobalt is a virtual space toolkit and browser.

More info: www.opencobalt.org
Gjallar is a highly customizable browser based issue management system.
More info: www.gjallar.se