Commercial software is any software or program that is designed and developed for licensing or sale to end users or that serves a commercial purpose. Commercial software was once considered to be proprietary software, but now a number of free and open-source software applications are licensed or sold to end users. Off-the-shelf software programs, such as games or those sold in computer specialty stores or even music stores and grocery stores, are some examples of commercial software.
Microsoft products such as the Windows Operating System and MS Office are some of the most well-known examples of commercial software.
Commercial software is normally licensed, not sold. It was once the domain of proprietary software, developed from scratch by a specific company to solve a specific problem or fill a specific niche and then licensed or sold to the people or organizations that needed them. This type of software includes financial, marketing and accounting software. During the last decades, however, some open-source applications have also become commercial software, licensed to customers as is or as part of a service.
Contrary to popular belief, open-source software does not necessarily mean free software. Depending on the distribution license, the former can be considered commercial software but comes with the source code to allow customization. Some commercial software applications may also be used freely for non-commercial use.