Additional OPAC (Online Public Access Catalogue) licenses are a low-cost solution to allowing several people throughout your organization to search the library/collection.
Each installation of ResourceMate® includes the OPAC. It is not necessary to purchase a license for computers that have a full copy of ResourceMate® installed on them.
Your OPAC license is a simultaneous license so the quantity you need will depend on how many search stations you want to have access at the same time.