Earlier quoted context omitted.
The copyright of a work belongs to its creator by default. (That's U.S. law; no contract is required to make that happen.) A standard contract for a contractor will stipulate that the copyright will be assigned to the client upon payment. If payment never occurs, the copyright stays with the work's creator.
> The copyright of a work belongs to its creator by default. (That's U.S. law; no contract is required to make that happen.) If it meets the criteria for a work-for-hire, the contracting party is the creator from the beginning for copyright law purposes (this is significant for reasons other than those under discussion; copyright transfers can reversed by the legal creator during a legally-specified window that occur…
On the other hand, if the work is created by an independent contractor or freelancer, the work may be considered a work for hire only if all of the following conditions are met:
- the work must come within one of the nine limited categories of works listed in the definition above, namely (1) a contribution to a collective work, (2) a part of a motion picture or other audiovisual work, (3) a translation, (4) a supplementary work, (5) a compilation, (6) an instructional text, (7) a test, (8) answer material for a test, (9) an atlas;
- the work must be specially ordered or commissioned;
- there must be a written agreement between the parties specifying that the work is a work made for hire by use of the phrase "work for hire" or "work made for hire."
It doesn't seem that software written by one person meets any of the nine criteria above. (A "collective work" seems to refer to something like a magazine that contains the writings of several authors.[2])
[1] https://en.wikipedia.org/wiki/Work_for_hire#Law_in_the_Unite...