If one looks at the EDA industry you will have to appreciate the breadth of applications Tcl is used in. Usually there is a Tcl interpreter with custom commands

If one looks at the EDA industry you will have to appreciate the breadth of applications Tcl is used in. Usually there is a Tcl interpreter with custom commands written in C for optimization. The ease with which one can quickly create interfaces between different tools I think is one of the contributing factors to its success. That and of course, the legacy codebase.