Linux
glibc
Finding glibc version
When you don't have access to the system package manager to find out what version of glibc you're running on
$ /lib/libc.so.6
GNU C Library (EGLIBC) stable release version 2.10.2, by Roland McGrath et al.
Copyright (C) 2009 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.3.4.
Compiled on a Linux >>2.6.26-2-amd64<< system on 2009-11-24.
Available extensions:
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
For bug reporting instructions, please see:
<http://www.eglibc.org/issues/>.