Open source licenses can be broadly divided into two categories based on whether they are:

• Permissive: These are similar to Internet Software Consortium (ISC), MIT, and BSD licenses. They have few requirements attached to them and they just require us to preserve copyright and limited warranty notices.
• Restrictive: These are similar to the GPL, and bind us to not only distribute the source code and modifications, either with the binary itself or at a later date, but also to distribute tools to build, install, and run the source.

However, some licenses might pollute modifications and derivative work with their own conditions, commonly referred to as viral licenses, while others will not. For example, if you link your application to GPL-licensed code, your application will be bound by the GPL too.

The virulent nature of GPL has made some people wary of using GPL-licensed software, but it's important to note that proprietary software can run alongside GPL software as long as the license terms are understood and respected.

For example, violating the GPLv2 license would mean losing the right to distribute GPLv2 code in the future, even if further distribution is GPLv2-compliant. In this case, the only way to be able to distribute the code again would be to ask the copyright holders for permission.