Are there programs out there like flash cs3?

dont gimmie stuff like torrents or programs riddles with viruses. im not trying to get illegal software. Its just..lets face it, adobe is expensive and i dont eactly have the money for it. When i wanted photoshop, i couldnt get it so instead i picked up paint tool sai, which if you didnt know is basically the same(even better in some ways) so yeah does anyone know where i can get free programs that are just as good as flash cs3?