TFS is a file system billed as a "Next-generation file system". It was created for Redox OS, as a replacement for ZFS. As of 2019, it still says on its official site that it is not ready for use, as only some of its components are complete.
Full-disk compression is built in, and a combination of trees and hash tables are used in its structure.
The full specification can be found in specification.tex. To render it, install texlive or another distribution with XeTeX, and run
- xelatex --shell-escape specification.tex
Then open the file named specification.pdf.