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It's scary, but even if you release something as open source, for free and free for people to modify as they please, you're still in a weird relationship with the people that use your software. You haven't exactly promised to do anything for them, and the code as-is is in itself a great gift... but on the other hand, there's an implicit acknowledgement that "yes, you can build on this". (Both the open letter and the response from Tom Dale seem to acknowledge that there's two sides to this issue, which is refreshing. Usually you get these really boorish "dude, it's open source, just fix it yourself will ya" responses.) It makes me wary of pushing any of my projects. I still open source pretty much everything I do, but usually with a big fat "for your edification, don't expect any support or ongoing development" disclaimer. (Also see fat's "What Is Open Source & Why Do I Feel So Guilty? at this video )