DwarfFS: a read-only compression file system
DwarFS is a read-only file system with a focus on achieving very high compression ratios in particular for very redundant data.
[...]DwarFS also doesn't compromise on speed and for my use cases I've found it to be on par with or perform better than SquashFS. For my primary use case, DwarFS compression is an order of magnitude better than SquashFS compression, it's 6 times faster to build the file system, it's typically faster to access files on DwarFS and it uses less CPU resources.
DwarfFS GitHub page
DwarfFS supports both Linux, macOS, and Windows, but macOS and Windows support is experimental at this point. It seems to have higher compression ratios at faster speeds than various alternatives, so if you have a use case for compression file systems - give DwarfFS a look.