Tangent: I’m a programmer who currently works as a cook. Kitchens are operating systems and many principles from OS design are applicable if you want to streamline service. Instead of programs, the kitchen must run multiple orders concurrently and efficiently. Containers, lowboys, refrigerators and the walk-in cooler are different cache/memory levels and become smaller the closer they are to your station. Batch processing (cooking, plating, finishing, etc.) will increase throughput, but sometimes latency is more important (you might want to immediately plate and finish an order if the customer has been waiting an hour). If chef says “on the fly” they want that order to preempt any existing orders in progress.
The term “operating system” might seem overly general but I think it’s pretty apt.
Less to me, because the product is the source. Github here is the way for distribution. It is a fairly nice medium for markdown files and without ads, but dedicated recipe sites have recommendations, comments and sometimes ways to directly order the ingredients.
So, basically every recipe site ever? If a recipe is posted on the internet, then it is, by definition "open source." Or are you referring to recipes posted with permissive, copy-left licenses, or are you referring to something else?