The Wolfram Symbolic Transfer Protocol (WSTP) allows you to call an external program from within the Wolfram Language even when that program is running on a remote computer. Typically, you need to start the program directly from the operating system on the remote computer. But then you can connect to it using commands within your Wolfram Language session.
Operating system on toad.wolfram.com
fprog -linkcreate -linkprotocol TCPIP
Link created on: email@example.com,firstname.lastname@example.org
Wolfram System session on frog.wolfram.com
External programs that are created using or always contain the code that is needed to set up WSTP connections. If you start such programs directly from your operating system, they will prompt you to specify what kind of connection you want. Alternatively, if your operating system supports it, you can also give this information as a command‐line argument to the external program.
|prog-linkcreate -linkprotocol TCPIP||operating system command to run a program and have it create a link|
|Install[LinkConnect["port1@host,port2@host",LinkProtocol->"TCPIP"]]||Wolfram Language command to connect to the external program|