By default, unclassified software which the government paid to develop should be released to the public as open source software (unless there’s a good reason not to).
I’m sure there will need to be exceptions. There would need to be some sort of guidelines to figure out when to grant those exceptions, and those guidelines should be developed though lively discussion. Most obviously, if it’s a special ingredient necessary for national security, then it should be classified and not revealed in any form. Export controls would also apply. But the exceptions should be that: Exceptions.