apply: a tiny library for chaining free functions into method call chains. For example, ever wanted tuples to have a .map() equivalent? let second = (12, 20, 30).apply(|x| x.1) does the trick.
Cargo subcommand that recursively finds and optionally wipes all "target" or "node_modules" folders that are found in the current path.
defer-drop: a newtype that defers object drops to a background thread.
cargo-asm can disassemble your bin. Useful for performance analysis and as an offline alternative to the Godbolt compiler explorer.
uniquote is an improved version of Path::display. It displays paths losslessly and escapes unprintable characters. #![no_std] is also supported without an allocator.
robotstxt: a native Rust port of Google's robots.txt parser and matcher C++ library.
- Native Rust port, no third-part crate dependency
- Preserves all behavior of original library
- Consistent API with the original library
- 100% google original test passed
JQL - A JSON Query Language CLI tool.
A faster tig:
(The only down side is it's an impossible project name to search for!)
cargo-spellcheck - spell & grammar checking for documentation comments
rpm-rs - a full rpm parser and synthesizer in rust (not a binding!)
Little traction so far but very useful when prototyping.
Helps decrease compile times for projects that need to include strings or bytes from files at compile time.
https://github.com/getditto/safer_ffi
Write safer FFI code in Rust without polluting it with unsafe code
https://github.com/imsnif/diskonaut
is a disk space navigator for the terminal (written in Rust, of course 
). (full disclosure: I am the author)
k9 - Rust Testing Library
A program that simulates the behavior of bodies that attract each other in real-time using wgpu.
print_bytes allows printing broken UTF-8 bytes to an output stream as losslessly as possible. Now, it can even print OsStr losslessly on Unix and Windows (when writing to Windows Console).
https://lib.rs/double-checked-cell-async
Async DoubleCheckedCell helps avoid race conditions when a program needs to initialize data asynchronously and lazily.
https://github.com/skallwar/suckit
SuckIT allows you to recursively visit and download a website's content to your disk.
Much faster than tools like HTTrack.
stdext is a crate with minor additional features for std. It is designed to be more agile in terms of getting a new std feature to your codebase, and less strict in terms of added features.
The assert_equal macro looks very useful. Checking the difference between structs is indeed painful with the standard assert_eq.