Patent licensing is today, as always, a very significant part of patent law. Since royalty licenses allow a patentee to realize pecuniary benefits from his invention without yielding ownership, as he would by an assignment, they are especially attractive to an inventor who anticipates considerable commercial success for his contribution, and who does not desire to lose all control of the invention for a lump sum, the adequacy of which must be, at best, speculative. From the licensee's standpoint, it is usually advantageous to be free of competition from others also operating under the same patent monopoly, at least within a limited area, and consequently an exclusive license is to his advantage. There is no question but that an exclusive license presents various advantages to both parties, and the proportion of patent licenses which are of an exclusive nature is therefore considerable.

A peculiar relationship, however, arises between patentees and their exclusive licensees, which does not arise in the case of an ordinary nonexclusive license, and which entails certain implied obligations on the part of the exclusive licensee. The patent licensee's obligations, while established in other fields of contract-license law, have recently been questioned, and will undoubtedly be the storm center of conflicting policies for some time to come. The subject is therefore considered to be of interest, and it is the purpose of this comment to summarize the position of the courts on the matter as it has been expressed up to the present time.