1) This it's their Objective-C development environment, includes GUI and more I think. See http://developer.apple.com/cocoa/
2) I'll skip over this one, as I'm not at all sure.
3) The normal installation format for osx are .dmg files, which are disk image files. These can be mounted, and then you simply drag the content over in your application folder. The tools for creating a .dmg come with OSX, so there is not much else you need.
4) I would get the latest version of OSX, but I'm not sure how fast it will run on an old machine like the G3.
Ragnar
2) I'll skip over this one, as I'm not at all sure.
3) The normal installation format for osx are .dmg files, which are disk image files. These can be mounted, and then you simply drag the content over in your application folder. The tools for creating a .dmg come with OSX, so there is not much else you need.
4) I would get the latest version of OSX, but I'm not sure how fast it will run on an old machine like the G3.
Ragnar