This page goes into even more nitty-gritty detail about open source hardware.

"Non-commercial" and "Open source"

Open source does not mean non-commercial. You can sell open source hardware or software, and others can sell your work -- as long as they distribute the source code as specified in the license. A license that specifies non-commercial work only may in fact not be open source, depending on whom you ask -- the Open Source Initiative specifically excludes 'noncommercial' licenses from their definition of open source. However, the Open Source Hardware Definition does not take a position on the matter.

Criticism

Limor Fried posted some great discussion about why non-commercial licenses may be counter-productive to open source projects.

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