Sounds like an awesome setup for your son. 
If you can get a mic for it, you should definitely Soundedit 16 and Sound effects. (Not sure if the second link is accurate.)
Both are great audio editing programs that me and my siblings loved playing with as kids. We would make silly recordings and modify the pitch and tempo and everything to make ourselves sound goofy. Then we went "professional" and started using tape cassettes.
(While still using the computer for sound effects.)
I highly recommend a mic for any child using a Mac.
Can't think of any other programs, oh, make sure that there are drawing apps. Like Kid pix, FineArtist, and ClarisWorks.
P.S. I don't know how many of these programs are SSW 6.0.8 compatible. As the lowest OS I've ever used was 7.1
If you can get a mic for it, you should definitely Soundedit 16 and Sound effects. (Not sure if the second link is accurate.)Both are great audio editing programs that me and my siblings loved playing with as kids. We would make silly recordings and modify the pitch and tempo and everything to make ourselves sound goofy. Then we went "professional" and started using tape cassettes.
(While still using the computer for sound effects.)I highly recommend a mic for any child using a Mac.
Can't think of any other programs, oh, make sure that there are drawing apps. Like Kid pix, FineArtist, and ClarisWorks.
P.S. I don't know how many of these programs are SSW 6.0.8 compatible. As the lowest OS I've ever used was 7.1