RedHat
======
$ cat /etc/redhat-release
Red Hat Enterprise Linux AS release 3 (Taroon Update 3)

$ uname -a
Linux dycc01 2.4.21-20.ELsmp #1 SMP Wed Aug 18 20:46:40 EDT 2004 i686 i686 i386
GNU/Linux

$ cat /proc/version
Linux version 2.4.21-20.ELsmp (bhcompile@tweety.build.redhat.com)
(gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-42)) #1 SMP Wed Aug 18 20:46:40 EDT 2004

$ cat /etc/issue
Red Hat Enterprise Linux AS release 3 (Taroon Update 3)
Kernel \r on an \m

SuSE
====
$ cat /etc/SuSE-release
SUSE LINUX Enterprise Server 9 (x86_64)
VERSION = 9
PATCHLEVEL = 3

$ uname -a
Linux ivr1 2.6.5-7.244-smp #1 SMP Mon Dec 12 18:32:25 UTC 2005 x86_64 x86_64 x86_64
GNU/Linux

$ lsb_release -a
LSB Version:    core-2.0-noarch:core-3.0-noarch:core-2.0-x86_64:core-3.0-x86_64:
                graphics-2.0-noarch:graphics-2.0-x86_64:
                graphics-3.0-noarch:graphics-3.0-x86_64
Distributor ID: SUSE LINUX
Description:    SUSE LINUX Enterprise Server 9 (x86_64)
Release:        9
Codename:       n/a