$ sudo yum --enablerepo=remi,remi-php55 install php
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
 * base: centos.mirrors.hoobly.com
 * epel: linux.mirrors.es.net
 * extras: linux.mirrors.es.net
 * remi: mirrors.mediatemple.net
 * remi-php55: mirrors.mediatemple.net
 * rpmforge: mirror.hmc.edu
 * updates: mirror.sanctuaryhost.com
 * webtatic: us-east.repo.webtatic.com
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package php.x86_64 0:5.5.14-1.el6.remi will be installed
--> Processing Dependency: php-common(x86-64) = 5.5.14-1.el6.remi for package: php-5.5.14-1.el6.remi.x86_64
--> Processing Dependency: php-cli(x86-64) = 5.5.14-1.el6.remi for package: php-5.5.14-1.el6.remi.x86_64
--> Processing Dependency: httpd-mmn = 20051115 for package: php-5.5.14-1.el6.remi.x86_64
--> Running transaction check
---> Package php.x86_64 0:5.5.14-1.el6.remi will be installed
--> Processing Dependency: httpd-mmn = 20051115 for package: php-5.5.14-1.el6.remi.x86_64
---> Package php-cli.x86_64 0:5.4.30-1.el6.remi will be updated
---> Package php-cli.x86_64 0:5.5.14-1.el6.remi will be an update
---> Package php-common.x86_64 0:5.4.30-1.el6.remi will be updated
--> Processing Dependency: php-pecl-zip(x86-64) for package: php-common-5.5.14-1.el6.remi.x86_64
---> Package php-common.x86_64 0:5.5.14-1.el6.remi will be an update
--> Processing Dependency: php-pecl-jsonc(x86-64) for package: php-common-5.5.14-1.el6.remi.x86_64
--> Running transaction check
---> Package php.x86_64 0:5.5.14-1.el6.remi will be installed
--> Processing Dependency: httpd-mmn = 20051115 for package: php-5.5.14-1.el6.remi.x86_64
---> Package php-pecl-jsonc.x86_64 0:1.3.5-1.el6.remi.5.5 will be installed
--> Processing Dependency: /usr/bin/pecl for package: php-pecl-jsonc-1.3.5-1.el6.remi.5.5.x86_64
--> Processing Dependency: /usr/bin/pecl for package: php-pecl-jsonc-1.3.5-1.el6.remi.5.5.x86_64
---> Package php-pecl-zip.x86_64 0:1.12.4-1.el6.remi.5.5 will be installed
--> Running transaction check
---> Package php.x86_64 0:5.5.14-1.el6.remi will be installed
--> Processing Dependency: httpd-mmn = 20051115 for package: php-5.5.14-1.el6.remi.x86_64
---> Package php-pear.noarch 1:1.9.4-28.el6.remi will be installed
--> Processing Dependency: php-xml for package: 1:php-pear-1.9.4-28.el6.remi.noarch
--> Processing Dependency: php-posix for package: 1:php-pear-1.9.4-28.el6.remi.noarch
--> Running transaction check
---> Package php.x86_64 0:5.5.14-1.el6.remi will be installed
--> Processing Dependency: httpd-mmn = 20051115 for package: php-5.5.14-1.el6.remi.x86_64
---> Package php-process.x86_64 0:5.5.14-1.el6.remi will be installed
---> Package php-xml.x86_64 0:5.5.14-1.el6.remi will be installed
--> Finished Dependency Resolution
Error: Package: php-5.5.14-1.el6.remi.x86_64 (remi-php55)
           Requires: httpd-mmn = 20051115
           Installed: httpd-2.4.9-1.x86_64 (installed)
               httpd-mmn = 20120211
           Available: httpd-2.2.15-29.el6.centos.x86_64 (base)
               httpd-mmn = 20051115
           Available: httpd-2.2.15-30.el6.centos.x86_64 (updates)
               httpd-mmn = 20051115
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest