An excellent idea and, financially, i don't think it would be a problem. Think about it, apart from funding the project and its developer, what reason do we have for buying the program? You don't get extra features, you don't get support, you just don't get asked to buy the product very so often. Nothing is stopping people from using the trial version indefinitely. If made ST an open-source project and accetepted donations i would not be surprised if he'd get as much money, or more, as he's getting now. Naturally not everyone would donate $60, but since more people can afford a lower amount i don't think that'd be an issue.
Personally i am hesitating to buy ST2 because of its closed nature. Normally it wouldn't be much of a problem but it's been months since we've heard anything about the state of development. The only one who knows where the program is headed and how fast is Jon, and that worries me. On the other hand, if the project were open source (and healthy), i would not hesitate to donate.
And, as Daniel points out, it could speed up development. The community around ST has built an amazing number of plugins, imagine wat they (some of them anyway) cold do with access to the source.
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