Most of the system libraries and some major apps have not been upgraded since 5.3, but a lot of smaller apps and utilities have, notably those created "in house" by our very enthusiastic developers such as zigbert, rcrsn51 and 01micko (plus more guys!)
What really has progressed significantly since 5.3 is the Woof infrastructure, bringing a plethora of bug fixes and enhancements. These improvements have made it imperative to release a new Wary (and Racy).
Racy is intended for "more modern" hardware than Wary, but not necessarily the very latest. Think perhaps most hardware a year or more old. Another way to separate them is that Wary is optimised for single-core CPUs, whereas Racy is optimised for multi-core CPUs.
Racy 5.5 has the 3.0.66 Linux kernel, configured without PAE support (so only accesses first 4GB of RAM), and for a i686 CPU. It has SMP (multi-core) support.
Rating: 3.0 out of 5.0 (Votes: 1) For your upload!