Full Metal Alchemist is a Japanese anime, based on a manga (comic book style) serial. The story unfolds through a series of flashbacks explaining how the two brothers became alchemists in order to bring their beloved mother back from the dead. The main principle of alchemy is equivalent exchange. In essence while attempting to bring their mother back they would have to give up something; unfortunately, they couldn't return her soul so one brother lost his body and the other lost his arm. Soon after, Edward, also had to give his leg in exchange for binding his brother's soul to a nearby suit of armor, so he wouldn't die. Al continued "living" but was trapped in this alternative body.
There are new episodes currently airing on Saturday nights on Cartoon Network's Adult Swim at 11 CST. The new animation is a remake of the original conforming more closely to the manga version of the story. It is called Full Metal Alchemist: Brotherhood.