It's a legal mess that doesn't work if your application isn't a website, and even then it's a problematic thing. Honestly, for considerable portion of its use,

It's a legal mess that doesn't work if your application isn't a website, and even then it's a problematic thing. Honestly, for considerable portion of its use, it works mainly because nobody looks too closely or trieso actually enforce it. The other considerable portion was/is bait&switch schemes involving dual licensing and having developers sign copyright transfer forms to parent org, which benefits from selling commercial license when someone runs afoul of compliance.