From the webpage [1 ]: "Frag is a highly flexible object-oriented Tcl extension written in pure Tcl. It is intended as a configuration and composition language for components written in other languages, such as Java, C, and C++. Frag runs in Tcl and Jacl."
(You may need an academic Elsevier/ScienceDirect subscription to read that article). (Not to mention a time machine.) (NEM 16 Dec 2005: Indeed, but that is the date given on the site...)