Seaside is the open source framework of choice for developing sophisticated and dynamic web applications. Seaside uses the power of objects to master the web. With Seaside, building web applications is as simple as building desktop applications. Seaside lets you build highly dynamic and interactive web applications.
AIDAweb is a Smalltalk web application framework used to build complex web applications with the latest seamlessly integrated HTML5 technologies for today's real-time web. MVC, REST, Mobile, WebSocket, you name it!
Amber is a language (derived from Smalltalk) and environment built for the web.
With Amber, client-side web development finally gets the power and productivity that exists in other Smalltalk dialects.
Teapot is micro web framework on top of the Zinc HTTP components, that focuses on simplicity and ease of use. It's around 600 lines of code, not counting the tests.