1. Sell 2. Gratis. 3. Gratis; donations welcome. #3 is barely adware. Sometimes people are extra appreciative of someone's work and want to express that thro

1. Sell 2. Gratis. 3. Gratis; donations welcome. #3 is barely adware. Sometimes people are extra appreciative of someone's work and want to express that through action; this just tells them how. On a personal level, I have no issue with an OSS author asking for donations. I draw the line at a company doing so. (An individual soliciting donations for something unrelated, like vim's "Help poor children in Uganda!" insert, isn't my favorite.)