The second Humble Bundle Mojam charity event is a go, now through Saturday, February 23, streaming live via the Humble Bundle website. Mojang - the developers of Minecraft - have joined forces with indie studios Grapefrukt, Ludosity, Oxeye Game Studio, Vlambeer and Wolfire Games for this year's Mojam, for a total of eight expected games (Mojang is making three). All proceeds from Mojam benefit Block by Block and the Electronic Frontier Foundation charities.

Watching Mojang and the other teams make games is absolutely free, though those interested can throw some money at Humble Bundle and get playable versions of the jam games at the end of it all. Last year's Mojam raised $460,000 for charity.

Fans got to help choose the themes for this year's Mojam, and there's a full list of the teams' assignments here. Mojang's three games, for example, are based on themes of French Nuclear Spaceship, Endless Nuclear Kittens and Nuclear Pizza War.