For GIS and remote sensing software, what are concurrent and single-use licensing?

Many GIS and remote sensing applications require either concurrent-use or single-use licensing (copyright) for their software. For example, ESRI uses single-use licenses for ArcView 3.x and concurrent-use licenses for ArcGIS products. ERDAS provides only concurrent licensing for its ERDAS IMAGINE application.

Single-use (node-locked) licensing

Single-use licenses, used with ArcView 3.x, permit software operation on only one computer at a time, and do not require a license service or license manager. An installation code activates the software. These licenses do not have a time-out feature; however, newer versions of the software require an additional license purchase.

Concurrent-use (floating) licensing

Concurrent-use licensing offers more flexibility than single-use licensing. A concurrent-use license allows you to install ArcGIS or ERDAS IMAGINE on as many computers as you want. The license manager, installed locally or on a Central License Service accessible to client computers via the network, serves as a librarian, and allows client computers to check out copies of software. For example, if a department purchased five licenses of software, that department can install the software on any number of computers, but can use only five licenses concurrently. This type of licensing is helpful for organizations with multiple users who do not use the software full-time.

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