Seems to be a columnar storage format that addresses some shortcomings in parquet. Thing is, though, that of all these formats the real winning feature is compatibility, which is (obviously) very hard to improve on, as anything new immediately loses.
Parquet is unfortunately very good just by virtue of being first, and so widely supported. The most widely used parquet version is the oldest version from 2013 (as per the paper itself), so parquet itself couldn't even supplant parquet. If you want to improve on it, you need to bring some serious results, which I don't think f3 does.
Also, my main gripe with parquet (single table per file) is not even addressed, so, also the name is a bit hyped up.
Also also, it seems to go out of its own way to include a compiled wasm binary for decoding, yet requires flatbuffers to parse that blob? Kind of defeats the purpose.
Its main result seems to be improved random access which, although certainly welcome, is not the point of columnar storage, as columnar storage was invented to exchange random access for something else: fast analytics. F3 seems to sacrifice fast analytics for the wasm decoder. I don't get it.
Maybe I'm being too cynical. Can someone help me out here?