This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

What is MathLM?

MathLM administers licenses for organizations running multiple instances of Mathematica with a network license. Network licenses provide a convenient and cost-effective way of making Mathematica available to multiple client machines in a networked environment. Instead of a separate license for each machine, a network license allows a specified number of copies of Mathematica to run concurrently on the network. MathLM automates the task of making sure you conform to the license agreement.
MathLM is installed on a single machine, known as the license server. Once MathLM is running, it acts as a gatekeeper for new Mathematica sessions. MathLM sets up the appropriate number of process slots for each class of computer covered by the network license. MathLM monitors the number of copies of Mathematica in use and issues licenses to clients until all available licenses are in use.
The number of concurrent processes that may run over the entire network is printed on your license certificate. You can increase the number of processes allowed with a license upgrade from Wolfram Research.
Mathematica consists of two components, the kernel and the front end. The Mathematica kernel performs computations. The Mathematica front end is the graphical notebook interface. MathLM keeps track of kernel and front end processes separately. The number n of processes printed on your license certificate generally gives you n front end process slots and n kernel process slots.
A client Mathematica process must request a license from MathLM before it starts taking user input or performing calculations. In order for clients to run Mathematica, MathLM must be running on the license server at all times. If the client machine making the request is not of a type covered by the license, or if all of the process slots are already in use, the client Mathematica process cannot be started.