Here is my OpenSprinkler Pi software implementation. It is written in Node.js for the backend with a REST API, and Angular.js for the frontend.
I originally wrote the software to interface with my Control4 system, and have included a driver for that as well.
It is in a pretty early stage of development, but it does work (at least what I have implemented). The frontend is as basic as it gets, and the backend lacks long term scheduling, but it is all being worked on, and will be updated frequently.
Please see the readme for installation instructions – I will add more detailed instructions as needed.
Cool, thanks for sharing and the detailed descriptions. I have never used Control4, but just did a quick search after seeing your post. Seems interesting. You may want to upload a couple of pictures (either here or on your blog) so that anyone who is interested can have a quick preview. Thanks.