The Tcl/tk language is not built into TCC-RT, and must be obtained separately. The version supported by TCC-RT is ActiveTcl 8.6 (free from


You must enable Tcl support in the OPTION / Startup page. If it is enabled, TCC-RT will automatically load a Tcl interpreter when it starts. If a suitable library is found, TCC-RT checks to see if you are running a .TCL file. If so, TCC-RT passes the file to your Tcl interpreter for processing.


It's not possible for TCC-RT to determine in advance whether you're running a Tcl or a Tk script. After executing the script, TCC-RT checks if a Tk window is running. If so, it enters a Tk event loop and waits for the window to be closed. If not, TCC-RT assumes it was a Tcl script and TCC-RT returns immediately.


Because of the way the Tk interpreter works, it is not possible for TCC-RT to maintain a persistent interpreter after executing a Tk script. TCC-RT will close the current Tcl/tk interpreter and create a new one the next time a Tcl / tk script is executed.


See also @TCL and @TK.