Different types of software licenses
Generally there are two types of software licenses that differ based on how they are viewed under copyright law.
- Proprietary licenses are often referred to as closed source. They provide customers with operational code. This users cannot freely alter this software. These licenses also usually restrict reverse engineering the software’s code to obtain the source code.
- Free and open source software (FOSS) licenses are often referred to as open source. Free and open source software (FOSS) source code is available to the customer along with the software product. The user is usually allowed to use the source code to change the software.
A more detailed list includes five types of software licenses. It makes finer distinctions among various types of open source licenses and proprietary licenses. This list includes the following:
- Proprietary. This is the most restrictive license type. Proprietary software licenses make it illegal to copy, modify or distribute the software. These licenses provide the software owners with the most protection from unauthorized use of the software.
- Permissive. This type of license will establish some requirements for distribution or modification of the software. It also has requirements for preserving license notices, copyrights or trademarks. There are several variations of permissive licenses, including Apache, BSD (Berkeley Source Distribution) and MIT licenses.
- Lesser general public license. Developers can link to open source libraries within their software and use any licensing type for the code.
- Public domain. This software is freely available. Anyone can use and change it or incorporate code from this software into an application. However, businesses should use caution as altered code may not meet enterprise quality and security standards. Companies should be wary of ambiguous licenses that appear to be public domain but do not explicitly say so.
- Copyleft. Licensed code may be distributed or modified as part of a software application or project if all code involved is distributed under the same license. New products containing old code with a copyleft license must comply with the restrictions laid out in the old code’s license.