https://www.gnu.org/software/libc/
Releases are available by source branch checkout via git and tarball via ftp.
Checkout the latest glibc 2.27 stable release:
git clone git://sourceware.org/git/glibc.git cd glibc git checkout --track -b local_glibc-2.27 origin/release/2.27/master
Release tarballs are available via anonymous ftp at http://ftp.gnu.org/gnu/glibc/ and its mirrors.