I'm a researcher in an Italian university and my main field of interest are bio-electric signals. I started to use Tcl/Tk as a tool language for various tasks required by the system management in our lab.
I'm actively maintaining Rivet. Apache Rivet is an open source collection of Tcl tools working together with mod_rivet, a software module that enables Apache to run Tcl code either standalone or embedded in HTML pages in the same fashion PHP does. Rivet current version is 2.1.0, available for download from the Apache Tcl Project . We are still maintaining the 2.0 version of Rivet (patchlevel 2.0.6) which runs with Apache 1.3
Years ago I developed with Tcl/Itcl a client/server application controlling a small network of PLC. The server communicated with the clients (and their GUI) with an XML based protocol independent from the PLC backend which had its own protocol. The whole client/server application was written in Tcl/Tk on a Linux system but happily worked on Windows with little effort for handling the incompatibilities (about 10 OS dependent lines / ~10000 lines of the whole application). Working with (I)Tcl in this field was very creative and greatly contributed to strengthen my interests in Tcl.
Using Rivet I developed also a small Itcl based framework for building websites. This project has little interest for experienced programmers and was meant as a way to become acquainted and fluent with web programming, its issues and technologies.
More recently I wrote for one my teaching classes another simple website framework that enabled my students to design a website and its contents writing plain text pages using an easy to learn XML template. My goal is to design this framework so that Tcl plugin handlers can be written separately for different sources of data (DBMS, Web services etc) and different formats/protocols (JSON, simple text...) In one of the greatest feat of imagination ever the project was called Rivetweb , Examples are a website about Biodiversity (in Italian), Rivet website and the website for a Master in Parks and Wildlife management (also in Italian)