"Use the lowest level possible" has always seemed rather stupid advice to me. What I suggest: use XML. Every programming language under the sun can spit out XML

"Use the lowest level possible" has always seemed rather stupid advice to me. What I suggest: use XML. Every programming language under the sun can spit out XML files, so you can generate them programmatically if needed, and it's not as if you'll ever sit there wishing you'd gone for a simpler format. Sachems make the files practically self-documenting and the tooling for them is brilliant.