What is the ruling on taking financial compensation for a free program through voluntary donation, and is it considered a corrupt sale, a gift, or something taken by the sword of modesty?

This transaction is a restricted gift. Donating to the owner means the user is not required to pay for the usage. A gift transforms into a sale if the giver stipulates specific money in exchange for it, as mentioned by Ibn Qudamah. Therefore, it is permissible to use the program for free, and this is neither a corrupt sale nor taking money by shame, as there is no room for shame here.