Newline-delimited JSON? I've used it informally, but I've never had the nerve to suggest it as an actual documented interchange format. It makes a lot of sense for things which CSV is often used for - dumping out big tables of data into files for shipping over FTP or similar - or even for logfiles with structured data entries. The tricky thing is having to restrict the JSON on each line to not contain any newline characters. Even though all legitimate JSON can be minified into a form which has the same semantics but contains no newlines, "JSON with no newlines in it" isn't a well defined standard.