If you intend to use your work commercially, you should be aware of licenses when you select what tools you are building on top of, or you may get bitten later.

If you intend to use your work commercially, you should be aware of licenses when you select what tools you are building on top of, or you may get bitten later. You may also wish to license your own work for others to use. If you have an opinion about when others should be allowed to use your work, licensing can be important for you to achieve that. You may not need to be aware if you have a legal department who do this for you, for example (or if you are willing to take the risk of legal action later).