Q: Why does the world need yet another binary JSON encoding? A: Excellent question, sock puppet! Fleece is different from BSON, PSON, etc. in that it's been carefully designed to not need parsing. In performance tests with other binary formats I found that, while they were faster to parse than JSON, the total time was still dominated by allocating and freeing the resulting objects, as well as the conversion from UTF-8 data to platform strings. (I was using Objective-C, but similar issues would arise if using STL or GLib or other collection frameworks.) The way around this is to structure the encoded data more like a memory dump, with "pointers" (relative byte offsets) and fixed-width random-accessible arrays. That's what Fleece does. As a result, it's many times faster to work with than JSON; literally 20x faster in the included benchmark run on a Macbook Pro.Q: Why did you only benchmark it against Cocoa's Foundation classes? Those are slow. Because Foundation is what I know and work with. I'd love to incorporate benchmarks of other frameworks; please send a pull request.