The module support over the unknown command requires, that the PL/Tcl call handler is compiled with -DPLTCL_UNKNOWN_SUPPORT. Regular Tcl scripts of any size (over 8K :-) can be loaded into the table pltcl_modules using the pltcl_loadmod script. The script checks the modules that the procedure names don't overwrite existing ones before doing anything. They also check for global variables created at load time. All procedures defined in the module files are automatically added to the table pltcl_modfuncs. This table is used by the unknown procedure to determine if an unknown command can be loaded by sourcing a module. In that case the unknonw procedure will silently source in the module and reexecute the original command that invoked unknown. I know, thist readme should be more explanatory - but time. Jan