To many people, open-source software is free of charge, and without any restrictions or licenses. But of course, open source (and its close cousin, free software) can only exist thanks to licenses, and copyright laws.  But wait — is software like a movie, a book, a machine, or none of these?  Or all of these?  What laws apply?  Hhow do they affect us, and what do they mean for the permissions we need in order to use, copy, and modify software?  What do open-source licenses mean to us as users, and developers?  And why is there so much confusion regarding licenses? In this talk, Brenda Wallace introduces us to the ideas of copyright, and to some of the murky aspects of copyright that software developers should understand, particularly if they’re contributing to open source.