Mod_dtcl is a free/open source implementation of server-parsed Tcl under Apache. It allows you to tightly integrate HTML with Tcl, a widely-used scripting language with many years of development invested in it. There are also many external Tcl modules that you can load into mod_dtcl, to create images, access databases, etc.
WT looks a bit like the ArsDigita Templating System, but is a lot simpler and less tied to a particular Web Server. It is a system for dynamic content which uses Tcl as its scripting language, and whose templates look like HTML with a minimum number of extra tags. The tags look like HTML tags, and a template can be viewed unprocessed in any browser. Pages can be built by a graphics person using a package like Macromedia Dreamweaver, with minimal need to hack on the HTML directly. Page styling and page engineering are separate, and are brought together when output is requested. It runs as a CGI script with Apache (and possibly with other servers, but this is untested). Web Templating can run as an Apache "Handler", or be embedded into your own Tcl scripts.
AppsLink is a Web service and platform that lets developers create small, tight, focused Web applications which can interoperate with other Web applications. The demo apps and libraries are the source to several AppsLinked apps, and some code to help developers develop AppsLinked apps.
OSSWEB is a Web application development framework for NaviServer consisting of the following parts: a security layer, a templating manager, a database layer, and a connection manager. Many modules are available, including news, weather, TV guide with PVR, contacts, administration, timesheets, problem/tasktracker, forums, shopping cart, calendar, photo album, and Webmail.
Tclog is a desktop Weblog application written in Tcl/Tk. Unlike most Weblog tools, it does not require server-side scripts. Instead, it uploads entries via FTP. It features RSS 1.0, HTML templates, TrackBack, Wiki-like formatting rules, indexes for the Namazu search engine, and more.
Apache Rivet is a system for creating dynamic Web content via a programming language integrated with Apache Web Server. It is designed to be fast, powerful and extensible, consume few system resources, be easy to learn, and to provide the user with a platform that can also be used for other programming tasks outside the web (GUIs, system administration tasks, text processing, database manipulation, XML, etc.). It is similar to PHP, except that it uses Tcl, and provides both HTML/Tcl pages as well as pure Tcl pages to aid the programmer in separating logic and presentation when necessary.