http://www.mud.ca/puzzler/JPuzzler/JPuzzler.html#
Click on the pyraminx.
Use Right-Mouse-Drag to rotate the puzzle in space.
Use Left-Mouse-Drag to perform moves. Drag a specific face to its destination to perform the move.
Use 'M' to Mix the puzzle, 'R' to Reset it, and 'B' to take back a move.