The Extensible project (which includes Ext Calendar Pro) is hosted at Github and should be available to anyone:
I was hoping to have a beta release out by now, but that hasn’t quite happened yet. The code should still be considered alpha quality, primarily because it’s been under heavy revision since the cut that went into Ext 3.3, and also because it is still not feature complete for what’s going to be in Extensible 1.0. However, I figured that there’s no reason not to let people check it out and start providing feedback.
It’s looking like it’s going to be at least a few weeks yet before the first proper packaged release is available. Once that’s done I’ll post again and discuss the status of specific features. A lot of the work that’s been going into the code lately has been focused less on new features and more on fixing bugs and improving the functionality and extensibility of the components that are there. It’s coming along nicely!
If you are interested in contributing to the project in any capacity please let me know. I’m going to try out Github’s built-in issue tracking, so if you find bugs, please post them. If you’re interested in adding docs or patching the code, feel free to fork the project and send me a note when you have something I should take a look at!