I've posted a list of the built-in atomic functions for the most recent version (0.9.3) of the Cat language.
I've just posted a table of all the approximately 100 primitive operations implemented in the current Cat interpreter at http://www.cat-language.com/primitives.html. I've also released the latest version of the code and executable version 0.9.3 Over the week-end I've made dozens of bug-fixes, cleaned up the code, and worked on the documentation. Now that the type-inference engine is stable things should go relatively smoothly and quickly from here on in. Hopefully in a week or two I should have a detailed walkthrough of the source code posted on CodeProject.com for those interested in looking closely under the hood.
For the uninitiated: Cat is a typed lightweight stack-based programming language inspired by Forth and Joy. Cat supports type inference which means that Cat looks and behaves like a dynamic language, but catches type errors at compile-time rather than run-time. This improves the safety and efficiency of Cat over dynamically typed languages.