Yeah, that is indeed the legal definition in the US of a work-for-hire. As is pointed out though, for non-employees (contractors) there's an enumerated list of

Yeah, that is indeed the legal definition in the US of a work-for-hire. As is pointed out though, for non-employees (contractors) there's an enumerated list of categories that that can be applied to. Writing software isn't in there. Although software and a web site designs might be considered an audiovisual work in some cases. Games and multimedia software are clearly audiovisual works. Accounting software, maybe not. Backend scripts, probably not. The second clause of the definition should probably be updated by Congress to reflect modern realities. However, as it has not been updated, an explicit copyright transfer is needed, or some form of licensing agreement. A lot of specialists for hire will insist on a license instead of an outright copyright transfers because they sure are not going to give away their core work permanently to one party, short of a buy out. With either a copyright transfer or licensing contract it doesn't need to be a work for hire, that issue is irrelevant, the contract is written to cover what you actually need.