Uh. Macromedia Flash is about it, and it's definitely not free. (I got the educational version for $90.) I think there might be a couple other programs that are easier versions of Flash, but I've never used them and don't know how much they cost. There's one called Swish, I think.
If it's just one or two files that you need to do this with, you could just download the trial version of Flash.