POLKA is a general purpose animation system that is particularly well-suited to building algorithm and program animations. One of the first foci for the system was to build animations of parallel programs and computations, but POLKA is ideal for animating good old serial programs too. POLKA is descended from the XTango system, but it is far more powerful and flexible. All of our most recent development was with POLKA, not XTango. POLKA supports color, real-time, 2 & 1/2 dimensional, smooth animations. To see examples (still frames) from Polka animations, click on visualization gallery. The focus of the system is on a balance of power and ease-of-use. POLKA provides its own high-level abstractions to make the creation of animations easier and faster than with many other systems. Programmers need not be graphics experts to develop their own animations. Polka also includes an interactive, front-end called Samba. Samba is an animation interpreter that reads one ascii command per line, then performs that animation directive