This page discusses the relevant changes introduced in CRUX 3.0. Everybody upgrading from the previous release is advised to carefully read the following notes.
More than 11 years after the release of CRUX 0.5 for i686, CRUX 3.0 is the first release for the x86-64 architecture.
At the time Per Liden had created CRUX, the i686 processor on base of the 32-bit Intel IA-32 architecture was state of the art and therefore chosen by him as the default optimization for CRUX. But nowadays the IA-32 arch is more or less obsolete, at least for desktop machines, and superseded by the x86-64 architecture.
CRUX 3.0 comes with a multilib toolchain which includes glibc 2.16.0, gcc 4.7.2 and binutils 2.23.1
CRUX 3.0 ships with Xorg 7.7 and xorg-server 1.13.0.
The ISO image is processed with isohybrid and is suitable for burning on a CD and putting on a USB drive.