RosettaCode is a website that collects together tasks on many topics and attempts to construct implementations of those tasks in as many different languages as possible. Tcl's examples there are particularly interesting to people learning the language as they illustrate many important techniques beyond those covered in the tutorials.
Note that this page does not list all examples implemented in Tcl. See Tcl's page on RosettaCode for that.
The Rosetta Code Helper is here to assist you.