While researching Swagger, a remarkable API library manager and code generator released under the Apache Licence 2.0 I wanted to know just what commercial use is allowed and the terms of that use. A quick search came up with tl;drLegal which documents software licenses. This is a very useful tool. While I’m not a lawyer and neither is tl;dr they claim that their information on many popular licenses have been verified by actual lawyers with expertise. Now of course you should probably go find the smartest open source IP lawyer you can find an get independent advice but if tl;drLegal says the license you want to use has restrictions on commercial use you should probably use that as a starting point.
The Apache License 2.0 is pretty free and easy. If I develop a commercial client/server application in Swagger for a client who is paying me I can sell them the intellectual property I create and they can use that plus Swagger and the code Swagger creates without fees as long as they include the appropriate copyright notice and license, state any changes made to their software and include any NOTICE file.