This is the GNU glibc-2.0.5c binary package (a.k.a. libc.so.6), including development libraries and header files. If you want to develop and run applications using GNU libc, just install this package (and edit your 'specs' file), and programs will be compiled using glibc by default: installpkg glibc-devel-2.0.5c.tgz To change your environment to use GNU libc for compiling you need to change the `specs' file of your gcc. This file is normally found at /usr/lib/gcc-lib///specs In this file you have to change a few things: - change `ld-linux.so.1' to `ld-linux.so.2' - remove all expression `%{...:-lgmon}'; there is no libgmon in glibc Note, this version of glibc was not compiled with the DES crypt add-on, although it does provide a crypt() function based on MD5. I'd have liked to include the real crypt(), but then wouldn't be able to export the resulting library. If you really need DES crypt(), you'll have to download the glibc-crypt-2.0.5.tar.gz add-on and compile it yourself. It can be found on prep.ai.mit.edu, in /pub/gnu. If you are outside the USA and Canada, do not download glibc-crypt-2.0.5.tar.gz from prep (to do so violates US export restrictions). There should be a readme file there that will point you to a non-US FTP site. This library does include the 'linuxthreads' add-on, which provides clone() and other threads-related functions. If you only want to run glibc applications, and wish to continue using libc5 for applications you compile yourself, install glibc-runtime-2.0.5c.tgz instead of glibc-devel-2.0.5c.tgz. If you decide to switch back to developing with libc.so.5 again, you'll first have to edit your 'specs' file to link with ldlinux.so.1. (In fact, it might be a good plan to just make a copy of the original 'specs' file when you edit it in the first place) Then, install the old 'libc.tgz' package again, and then remove glibc like this: cd installpkg libc.tgz cd /var/log/packages removepkg glibc-devel-2.0.5c Have fun!