What is traditionally meant by “floating licensing”?

The conventional floating license model enables an ISV to sell a product based on a concurrent user limit as an alternative to selling the product based on seat licenses. The ISV distributes a floating license server that is installed at an end customer’s premises, and provides licenses for the server that constrain the limit on the number of instances of active applications that run on the end customer’s network. Whenever an instance of the protected application is started, it checks out a floating license from the license server, which maintains an in-memory reference count of active requests. While the application is running, it periodically issues heartbeats to the license server in order to let the license server know that it is still running and in order for the application to be assured the license server has not been disconnected to bypass license checks. At the time of orderly application termination, the application checks in the floating license. In the event of an application crash, the license server frees the application’s license upon detection of missed hearbeats. When an application wishes to check out a license for offline use, it does so by proxy – a “borrower” application performs the checkout on behalf of the application.