Basically, Legend is a d20 system based off of DnD, that is currently in a Pay-What-You-Want release. During this pay what you want release, all donation go to awesome charity organization, Child's Play. They have also promised free updates and expansions if there is demand for it. The demand appears to be there, as in five days, they have had over 4,000 downloads and earned over $4,000 for Child's Play.

Interview with creators of Legend(who explain more about the game than I ever could): http://www.mesapress.com/a-e/2011/11/19/2541/

Keep track of progress/download the pdf at: http://www.ruleofcool.com/

*For those wondering, there is no listed rules for bring DnD things into the game.