It depends on what your script will be doing as to whether or not to use tclsh or EEM Tcl. For a script that needs UDP socket access or direct terminal manipulation (e.g. screen refresh, single-character reading, etc.) then tclsh is the way to go. If you need to do complex command interaction, want to easily send email, and get the benefit of the EEM security and scheduling perks, then EEM is the way to go. In general, I find EEM Tcl to be a bit richer for the scripts I write. This is especially true if you consider not using the none ED, and rather use the enhanced CLI ED to add your command to the parser tree. So, instead of typing "event manager run script.tcl", you can create a truly custom command such as "show scott tudor" that supports context-sensitve help and tab completion.