Since most people have MAX 3.5.8, the MAX 3.5.9 update 
provides only those files that have changed since MAX 3.5.8. 
If you need the external objects that have changed since 3.5 was released, 
download MAX 3.5.8 for a complete collection of the external objects.

MAX 3.5.9(MacOS8).sit.hqx is for users who have authorized their hard drive
with the MacOS 8 compatible MAX authorization disk. Users who don't have this 
authorization disk should use MAX 3.5.9(MacOS7).sit.hqx. For information on 
how to obtain a MacOS 8 compatible MAX authorization please contact Opcode
Customer Service.