GPLv3

A draft of the third version of the General Public License--under which much open-source and free software is developed and distributed (that's "free," Richard Stallman has famously explained, "as in 'free speech,' not as in 'free beer.'") is on-line for public review and comment. It's worth reading if you're interested in the current legal implications of making and sharing stuff you made; that there are legal implications at all fascinates me. It's also a nice introduction to copyleft.