Rust-Based Redox OS Had A Busy Year With Rewriting Its Kernel, Writing A File-System
Among the work done by this set of developers working on this original operating system in Rust was rewriting their kernel entirely, improving their memory allocator's performance significantly, Internet support on Redox, and more games/applications are beginning to work on Redox. Developers are also working on "TFS" as the new default file-system in development, rustc support is in place, and there is at least one full-time developer working on the project.
For those curious about the TFS file-system, it's self-described as "a modular, fast, and feature rich next-gen file system, employing modern techniques for high performance, high space efficiency, and high scalability. TFS was created out of the need for a modern file system for Redox OS, as a replacement for ZFS, which proved to be slow to implement because of its monolithic design. TFS is inspired by the ideas behind ZFS, but at the same time it aims to be modular and easier to implement."
More details on the state of Redox OS can be found via this blog post.