As Section 6.2 describes, installing Mac OS X software is as easy as dragging an application’s icon to your hard drive, or occasionally having to double-click a package icon and run through a few prompts in the Installer application. Thereafter, everything Just Works.
Installing software for Darwin, the Unix side of Mac OS X, is not always so easy. Since Mac OS X’s graphical interface tends to keep Darwin and its activities invisible in the background, many Mac OS X users never need to worry about this. However, through Darwin, you have access to a whole world of largely open source software written for the Unix operating system. In Mac OS X’s “factory” state (with the Developer Tools installed), you can immediately start installing and using Unix software that uses a command-line interface (or has no interface at all, as with system daemons; see Chapter 5). If you install the X Window System (as described in Chapter 23), you can start using all manner of GUI-using Unix software as well.
This chapter discusses the various strategies you have for Darwin-side software installation, including DIY-style compiling from raw source code and the rather friendlier use of package managers.
A package management system uses a local database to keep track of software packages installed on the machine and the dependencies that run among them. New packages consult this database to see if other packages whose presence they depend upon are ...