I’ve been experimenting with archive format design and built 6cy as a research project.

The goal is not to replace zip/7z, but to explore: • block-level codec polymorphism (different compression per block) • streaming-first layout (no global seek required) • better crash recovery characteristics • plugin-based architecture so proprietary codecs can exist without changing the format

Right now this is an experimental v0.x format. The specification may still change and compatibility is not guaranteed yet.

I’m mainly looking for feedback on the format design rather than performance comparisons.

Thanks for taking a look.