Licence compliance is irrelevant to submitting your own contributions. Typically when you submit contributions to open source software you retain ownership of t

Licence compliance is irrelevant to submitting your own contributions. Typically when you submit contributions to open source software you retain ownership of the copyright, but grant a licence to the project owners to use it (and therefore to others because OSS licences includes a term about relicencing by definition). This doesn't stop you from granting others a different licence, or using it yourself however you like. As an example, if I write and publish a complete program or library under GPL (or any other licence), then that doesn't stop me from selling the same thing under a proprietary licence. Qt is a classic example of this. Similarly, if I make a small contribution to a library under GPL, or any other licence, then that doesn't stop me from re-licensing my small chunk of code however I like, or reusing it internally under non-GPL terms - because it's mine! The exception to this is those few projects that require you to actually assign copyright. Most notably this includes the FSF (except GCC as of a couple of months ago), their reasoning being that this makes it easier for them to litigate against violaters of the GPL, because only the copyright owners can sue.