Is GPL OK For Commercial Use?
Software under the GPL may be run for all purposes, including commercial purposes and even as a tool for creating proprietary software, such as when using GPL-licensed compilers. Users or companies who distribute GPL-licensed works (e.g. software), may charge a fee for copies or give them free of charge.
In general terms, if you use GPL-licensed code in your program that you wish to distribute to others, then you must also license your program under the GPL. ... This has implications for proprietary and/or commercial software developers, as many popular and important libraries are licensed under the GPL.
Using GPL code in your software: the essentials - Clendons
The GPL just says a person with the binary can request source. So if only the people with the binary are in the company then only they can request source. There is no field of use restriction in the GPLv2 - users are free to use if however they like, including for commercial purposes.
GNU General Public License (v2): can a company use the ...
Can I use GPL 3.0 commercial?
Use the code for commercial purposes: Like GPL v2, GPL v3 imposes no conditions on the internal use of the software. ... Distribute copies or modifications of the code: As long as these modifications are also released under the GPL v3 license, they can be distributed to others.
Open Source Software Licenses 101: GPL v3 - FOSSA
GPL is enforceable as it's essentially a copyright license. The copyright holders of the GPL software can choose to enforce the GPL on the distributed or derivative works of the software. For example, the FSF holds the copyrights on many pieces of the GNU system, such as the GNU Compiler Collection.
Top 10 GPL License Questions Answered - WhiteSource