SASHIMI, like all great things, is RAW! RAW, like sushi, sashimi means “uncooked”. A RAW installer is most suitable for use on uncooked, stock, or lite ROMs. It helps users who would prefer to install all of their own apps an easy semi-automated way to do it. Of course it can be be used on cooked ROMs too.

http://forum.xda-developers.com/showthread.php?t=396559