I believe swf stands for "Shockwave Flash". The extension .swf is indicative of a movie created in the program "Flash", which is put out by "Macromedia". As for viewing it, I've viewed .swf files, I don't believe you need any special program to view them. I've viewed movies on the net that are .swf extensions and they just load and view in the browser window.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi