Yes, you can use Open Source software for commercial purposes. According to the legal definition of Open Source software, you can add Open Source code to your proprietary software and sell it. These free resources are building blocks that speed up projects for countless software teams worldwide. However, in some instances, you cannot place limitations on the people who receive and use these programs. The licenses on some Open Source software sources have terms and conditions you should observe to avoid a lawsuit. GNU-licensed Open Source software and other permissive sources are ideal for commercial products because they have the fewest restrictions.