Hi, On the boost document page it has entry of the library: C++/Tcl - C++/Tcl is a library that allows the easy integration of C++ and Tcl. If I follow the link of the library, it will direct me to: http://cpptcl.sourceforge.net/ And I can download source code of the library. But one problem I found was that there is a header file "tcl.h", included as header by the source code, and it was missing. So I suppose this C++/Tcl library requires TCL pkg from third party, e.g. ActiveState. But the pkg from ActiveState is not free. I am using C++ in MS VC++ 2005 express to integrate with tcl, and I am looking for tcl library for this. I am not sure what TCL library that the boost C++/Tcl developers and users are using. If somebody could give some comments or suggestions what TCL pkg can be used for the boost C++/Tcl library, it is appreciated. Thank you! Fanzhe