Any recommendations or popular reading?
I realize some choices are for proprietary reasons, then compression, but that aside, there seems to be thousands of choices available.
Compared to the web, using json etc, and releasing a schema, but not necessarily creating a new file extension.
OTOH, you have to know when no to use it and step up (down?) to something that is text editor hack-able (XML!?) or has barn burner I/O abilities (yah actually just dumping raw buffers with regularized binary data to disk). Or for that matter is used to exchange data with other apps with other services (JSON, and the long list of other data dependent formats, although for at rest exchange I have to point at XML again).