Email Hosting Providers

SPFSPF

SPF Usage Statistics · Download List of All Websites using SPF

The Sender Policy Framework is an open standard specifying a technical method to prevent sender address forgery.

Operating Systems and Servers

Parallels Plesk PanelParallels Plesk Panel

Parallels Plesk Panel Usage Statistics · Download List of All Websites using Parallels Plesk Panel

Host and manage websites and servers at any scale, includes virtualization software.

Web Servers

ApacheApache

Apache Usage Statistics · Download List of All Websites using Apache

Apache has been the most popular web server on the Internet since April 1996.