1. Get the code from https://gist.github.com/k3rni/5400291
2. Upload, paste or type it into the Computercraft editor
3. Alternatively, install cc-get and then run cc-get mctechtree
4. Run it: mctechtree <item name>

1. Clone the repository
2. Ensure you are working from the latest HEAD
3. Create a new branch for your changes, name it appropriately (e.g. the mod you're adding recipes for, a feature name)
4. Write recipes and/or code.
5. Submit a pull request.

Run techtree.rb after each set of changes in the recipe files. It will tell you what's wrong - missing items, naming conflicts, bad definitions. Check your YAML files with a validator (such as http://yamllint.com) if you're not sure, as these errors tend to give rather cryptic messages.