Red Hat

# service httpd start
Starting httpd: Syntax error on line 6 of /etc/httpd/conf.d/php.conf:
Cannot load /etc/httpd/modules/libphp4.so into server: /lib/tls/libc.so.6: version `GLIBC_2.4' not found (required by /lib/libgcc_s.so.1)
                                                           [FAILED]

# strings /lib/tls/libc.so.6 | grep GLIBC
GLIBC_2.0
GLIBC_2.1
GLIBC_2.1.1
GLIBC_2.1.2
GLIBC_2.1.3
GLIBC_2.2
GLIBC_2.2.1
GLIBC_2.2.2
GLIBC_2.2.3
GLIBC_2.2.4
GLIBC_2.2.6
GLIBC_2.3
GLIBC_2.3.2
GLIBC_2.3.3
GLIBC_2.3.4
GLIBC_PRIVATE
#

# rpm -ivh glibc-2.4-4.i686.rpm
warning: glibc-2.4-4.i686.rpm: V3 DSA signature: NOKEY, key ID 4f2a6fd2
error: Failed dependencies:
    glibc-common = 2.4-4 is needed by glibc-2.4-4.i686
    gdb < 6.3.0.0-1.111 conflicts with glibc-2.4-4.i686
    glibc > 2.3.4 conflicts with glibc-common-2.3.4-2.i386
#

# rpm -ivh glibc-common-2.4-4.i386.rpm 
warning: glibc-common-2.4-4.i386.rpm: V3 DSA signature: NOKEY, key ID 4f2a6fd2
error: Failed dependencies:
    glibc < 2.4 conflicts with glibc-common-2.4-4.i386
#

# cat /etc/httpd/conf.d/php.conf 
#
# PHP is an HTML-embedded scripting language which attempts to make it
# easy for developers to write dynamically generated webpages.
#

LoadModule php4_module modules/libphp4.so

#
# Cause the PHP interpreter to handle files with a .php extension.
#
AddType application/x-httpd-php .php
# AddType application/x-httpd-php-source .phps

#
# Add index.php to the list of files that will be served as directory
# indexes.
#
DirectoryIndex index.php
#