Turns out that under IRS Regulation §1.861–18 there are a fair number of situations where money earned from selling a copyright right of software is treated as a capital gain. (And fortunately for me, I fall under one of those cases)
Those who have interest in this can see the regulation here:
Are you licensing (as you said earlier) or selling (usually referred to as “assigning”). In real estate terms it’s the difference between selling a home and renting it out.
