via http://mac.scripting.com - Network Computing ... Apple OS X Upgrade Delivers Fast, User-Friendly Unix OS ...

In addition, by installing the developer tools (available on CD or by free download), I had access to a project builder and C/C++ compiler. I've searched for free C compilers for the classic Mac OS before and couldn't find any. Now anyone can be a Mac developer, which may mean a revival of the Mac shareware community.