Loadable C extensions Tcl lets you augment the language with commands written in C. This gives added speed and the ability to handle binary data. I will be providing more and more loadable versions of bits of zircon as time goes on so I would appreciate some feedback from people on how to create them on different systems. Currently the only loadable module is in the directory plugins/Sed. On Solaris I give the commands : gcc -c -fPic sed.c ld -G -z text -o libSed.so sed.o And this creates me the library libSed.so I then run tclsh and give the commands : pkg_mkIndex . *.tcl *.so exit This will pick up the loadable module whcih will be used in preference to the tcl version which uses a helper program. I don;t know how to do this on any other system other than Solaris so I cant do a Makefile just yet - so let me know how its done on your system!! Thanks L.