There is a pre-built PHP 4 binary coming with LSWS, however, you should build your own PHP binary using matching configuration options used by Apache mod_php.

Get a list of compile options (type 'php -i' and look for the line with 'Configure Command ⇒' as shown below:)

root@test ~># php -i
phpinfo()
PHP Version => 5.3.10
...
...
Configure Command =>  './configure'  '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' \
'--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' \
'--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' \
'--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' \
'--infodir=/usr/share/info' '--cache-file=../config.cache' '--with-libdir=lib64' '--with-config-file-path=/etc' \
'--with-config-file-scan-dir=/etc/php.d' '--disable-debug' '--with-pic' '--disable-rpath' '--without-pear' \
'--with-bz2' '--with-exec-dir=/usr/bin' '--with-freetype-dir=/usr' '--with-png-dir=/usr' '--with-xpm-dir=/usr' \
'--enable-gd-native-ttf' '--with-t1lib=/usr' '--without-gdbm' '--with-gettext' '--with-gmp' '--with-iconv' \
'--with-jpeg-dir=/usr' '--with-openssl' '--with-zlib' '--with-layout=GNU' '--enable-exif' '--enable-ftp' \
'--enable-magic-quotes' '--enable-sockets' '--with-kerberos' '--enable-ucd-snmp-hack' '--enable-shmop' \
'--enable-calendar' '--with-libxml-dir=/usr' '--enable-xml' '--with-system-tzdata' '--with-mhash' \
'--enable-force-cgi-redirect' '--libdir=/usr/lib64/php' '--enable-pcntl' '--with-imap=shared' '--with-imap-ssl' \
'--enable-mbstring=shared' '--enable-mbregex' '--with-gd=shared' '--enable-bcmath=shared' '--enable-dba=shared' \
'--with-db4=/usr' '--with-xmlrpc=shared' '--with-ldap=shared' '--with-ldap-sasl' '--enable-mysqlnd=shared' \
'--with-mysql=shared,mysqlnd' '--with-mysqli=shared,mysqlnd' '--with-mysql-sock=/var/lib/mysql/mysql.sock' \
'--with-oci8=shared,instantclient,/usr/lib64/oracle/11.2/client64/lib,11.2' \
'--with-pdo-oci=shared,instantclient,/usr,11.2' '--with-interbase=shared,/usr/lib64/firebird' \
'--with-pdo-firebird=shared,/usr/lib64/firebird' '--enable-dom=shared' \
'--with-pgsql=shared' '--enable-wddx=shared' '--with-snmp=shared,/usr' '--enable-soap=shared' \
'--with-xsl=shared,/usr' '--enable-xmlreader=shared' '--enable-xmlwriter=shared' '--with-curl=shared,/usr' \
'--enable-fastcgi' '--enable-pdo=shared' '--with-pdo-odbc=shared,unixODBC,/usr' '--with-pdo-mysql=shared,mysqlnd' \
'--with-pdo-pgsql=shared,/usr' '--with-pdo-sqlite=shared,/usr' '--with-pdo-dblib=shared,/usr' '--without-sqlite3' \
'--with-sqlite=shared,/usr' '--enable-json=shared' '--enable-zip=shared' '--without-readline' '--with-libedit' \
'--with-pspell=shared' '--enable-phar=shared' '--with-mcrypt=shared,/usr' '--with-tidy=shared,/usr' \
'--with-mssql=shared,/usr' '--enable-sysvmsg=shared' '--enable-sysvshm=shared' '--enable-sysvsem=shared' \
'--enable-posix=shared' '--with-unixODBC=shared,/usr' '--enable-fileinfo=shared' '--enable-intl=shared' \
'--with-icu-dir=/usr' '--with-enchant=shared,/usr' '--with-recode=shared,/usr'

Another configure example for PHP 5.4

 '--with-mysqli' '--with-mysql' '--with-zlib' '--with-gd' '--enable-shmop' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--enable-mbstring' '--with-iconv' '--with-mcrypt' '--enable-pdo' '--with-pdo-mysql' '--with-curl' '--with-litespeed' '--enable-bcmath' '--with-bz2' '--enable-calendar' '--enable-ftp' '--with-openssl' '--with-gettext' '--with-mhash' '--enable-soap'

Compile PHP from LSWS Admin Console (Actions ⇒ Compile PHP) with mod_php compile options.

Note: './configure' needs to be removed when cut and paste to LSWS Admin Console. That is, just cut and paste the options above starting from “'--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' …” (remove “Configure Command ⇒ './configure' ”)