Apple has released version 3.1.2 of Xcode, "Apple's tool suite and integrated development environment (IDE) for creating Mac OS X Universal Binaries that run natively on PowerPC and Intel-based Macintosh computers. The IDE provides a powerful user interface to many industry-standard and open-source tools, including GCC, javac, jikes, and GDB. Xcode is designed to fully support the Carbon and Cocoa frameworks and Java. It contains templates for creating applications, frameworks, libraries, plug-ins, Java applications and applets, and command-line tools. Developers can use Xcode to construct a user interface, test code performance, and perform many other common development tasks." "3.1.2 is an update release of the developer tools for Mac OS X. This release provides additional GCC and LLVM compiler options, general bug fixes, and must be installed on Leopard, Mac OS X 10.5.0 and higher."
Xcode and its updates are free beer. With Mac OS X, Apple wisely stopped charging for developer tools. You'll still need an ADC membership (including the free membership) to get a copy.