FOSS gamedev and creative worlds

Hello everyone. I'm trying to build a mod furnace, or blender, that enables blending of two or more items into one (of course the recipes are included, as I am thinking of blending limestone and clay into cement), but I am not sure how I can achive this. It's quite complicated...

How can I do it? If you can provide sample code then it's great. Thanks.

Use technic alloy furnace.. just add recipes and done:)