Retrieve metadata from any DOI minter in one GUI and offer content negotiation

I need to resolve DOIs for text and data (and software). I want to use exactly one GUI and don’t want to bother who minted the DOI. As a bonus I would appreciate it if this one GUI would give me the “better” (more complete? more current? …) metadata. You may store my preference about content negotiation in a cookie, because I always want BibTeX. Many thanks. --Alexander