gooby

exactly what it says: if true, if youre casting a spell and then try to move, it will cancel the spell from casting and move you. otherwise i think it'd prevent you from moving while casting

of course its possible with source edits
 
wishy made a source mod a couple months ago but it seems he removed it for some reason. here are the threads, maybe they could be of some use?

EDIT: also even though it seems the patches have been suddenly removed, you shouldnt apply old patches cuz it could just break your game, but you can still take a look into them to get an idea