Ok, this is killing me, i need to install this damn app, i downloaded already, the file has an .sit extension, and there is also an .hqx one, how do i execute this things!?
If we are talking about Mac OS 9.0.x, StuffIt Expander 5.5 was included with the rest of the system. As I recall, you'll find it in Applications (Mac OS 9)/Internet/Internet Utilities/Aladdin Folder along with DropStuff 5.5.
The first time Apple stopped including StuffIt Expander was with Mac OS X v10.4.