Xshell is a powerful and user-friendly terminal emulator (namely implementing the operation and management to remote hosts in a local computer) from South Korea, supports SSH1, SSH2, FTP, SFTP, Telnet, rlogin, and Serial protocols. It enables users to directly connect to the remote hosting via Internet, so as to easily control Linux servers on Windows.

CentOS (short for Community ENTerprise Operating System) is a free, open-source, enterprise-class and community-supported computing platform that derived from the same source code with Red Hat Enterprise Linux OS. At present, there have been increasing Internet services or applications around the world that require high stability (including a variety of purposes of servers and business applications) are running on it, rather than RHEL.