Documentation
PyroCMS is a modular, theme-able, lightweight CMS built with the popular PHP framework CodeIgniter. It is designed to be simple enough for any developer to create modules and for any end user to understand how it works.
We focus on simplicity and will avoid adding in “buzz” power features into a default installation that could confuse users. PyroCMS will make more sense to your clients than other systems, giving you more time to work on new sites instead of supporting old ones.
v2.1.x - Development
Development means that v2.1 is not quite ready for use in production by you or your clients, but it is available for people who like to test new features, add-on developers, theme designers, etc.
v2.0.x - Stable
This is the stable version that you should be using on your websites. We'll always support the stable version and suggest if you're on anything that you upgrade as soon as you can.
v1.3.x - Legacy
Why are you still using v1.3? We know upgrading can be tough but you're missing out on loads of cool stuff. Still, here are the docs for 1.3.
API
No API Documentation for this version, its too darn old.