The Sherman Brothers
I used to watch this fairly often when I was younger, but I never paid attention to the credits until today (I watched this with my niece in an effort to get her to watch something besides Caillou, but I digress). I never realized the Sherman brothers made the songs for this, but now that I know, I say to myself, "No wonder I like the songs so much!"
I also never realized that Hanna-Barbera made this movie, either. Of course, I didn't really know who they were until recently, since I had never really grown up with any of their shows.