What is the difference between commercial and proprietary software?
To quote the 1913 Webster’s, {Proprietary articles}, manufactured articles which some person or persons have exclusive right to make and sell. –U. S. Statutes. {Commercial}. Of or pertaining to commerce; carrying on or occupied with commerce or trade; mercantile; as, commercial advantages; commercial relations. Princely commercial houses. –Macaulay. Proprietary software is software that can be legally modified or distributed only by some authorized set of persons. So by definition proprietary software cannot be free software. Software is commercial if some corporation is distributing it and trying to make money from it, either via direct sales or via maintenance and support. Many corporations have made money by distributing, supporting, and maintaining free software, so it is possible for a piece of software to be both free and commercial. Anyone can sell a support contract for free software, and access to the source code allows such support to include not just hand-holding but also
