SME Server (formerly known as e-smith) is a Linux distribution based on CentOS offering an operating system for computers used as web, file, email and database servers. It employs a comprehensive UI for all management-related tasks and is extensible through templates.
The letters SME stand for Small to Medium Enterprise, as that is the target market of the software. One of the most notable features of this distribution is its template system. SME Server 9.2 is based on CentOS 6.7 which is based on Red Hat Enterprise Linux (RHEL). Version 32Bit (with PAE Support) and 64bit now available. Running Apache 2.2,MYSQL 5.1,PHP 5. Some additional Addons are available on the current "stable" Version, they are called "Contribs".