MySQL 5.5 on CentOS/RHEL 6.7 via Yum

Redhat Enterprise Linux (RHEL) 6.x and CentOS 6.x have been providing MySQL 5.1 in its distribution since that was the active stable branch when RHEL 6.0 was released. Since then, Sun/Oracle have released MySQL 5.5, so the Webtatic Yum repository has added them to its web stack, which now provides updated versions of all the AMP in LAMP.

Nginx 1.12 on CentOS/RHEL 7.4 via Yum

Nginx 1.12.1, released 11th July 2017, has been added as a package on the Webtatic EL7 yum repository for CentOS/RHEL 7.4

LNMP (Linux Nginx MySQL PHP) is an alternative web-stack to LAMP (Linux Apache MySQL PHP), with Nginx being better suited to serving static files, due to being able to handle many more simultaneous connections with a lower process count and memory footprint.