1) American invention 2) Free software programmed in C 
[GTPase] TCL is a small (~21 kDa) signaling G protein (more specifically a GTPase), and is a member of the Rho family of GTPases.,. TCL (TC10-like) shares 85% and 78% amino acid similarity to TC10 and Cdc42, respectively. TCL mRNA is 2.5 kb long and is mainly expressed in heart. In vitro, TCL shows rapid GDP/GTP exchange and displays higher... Tcl (originally from Tool Command Language, but conventionally spelled `Tcl` rather than `TCL`; pronounced as `tickle` or `tee-see-ell`) is a scripting language created by John Ousterhout. Originally `born out of frustration`, according to the author, with programmers devising their own languages intended to be embedded into applications...
Tool Command Language, details ...
(In topic `Web Development`) Tcl (pronounced ‘Tickle`) is a scripting language
Tool Command Language
Tool Command Language