Boeing Satellite Systems (El Segundo California) uses [Tcl] extensively in its Ground and Test Equipment operations. Large and complex products for both internal and external customers use Tcl as the core language, with extensions written in [C]/[C++]. Ease of integration with existing legacy applications facilitated its initial use. [[[incr tcl]/tk]] is the primary language extension used, and without it, continued use of Tcl for the large projects would be questionable. <> Company