This is how the Sun shines: Hydrogen is fused into helium. Press p to spawn protons. Press space to erase all protons. There's something wrong: Hover over the protons and you will see them turn into neutrinos and positrons. Click the i for info and the periodic table.
Encyclopedia of the Sun by Cambridge. UPDATE: This is now a sim. It may get a little laggy, especially if you're on a slow computer. After nine hours of being inactive for christmas this blew up to 200 views. wow did not expect that. A blowout for 370 views and two remixes!