Frequently Used Crates

Dec 19, 2025

By name

NOTE: The crates are ordered in alphabetic order.

anyhow

Create error types on the fly without having to define them. Use this when you only care about the presence or absence of an error without worrying about the actual error.

https://crates.io/crates/anyhow

clap

Program command line arguments easily.

https://crates.io/crates/clap

futures

Utilities for async programming.

https://crates.io/crates/futures

hashbrown

Rust port of Google’s SwissTable

https://crates.io/crates/hashbrown

Swisstable links

  1. https://abseil.io/blog/20180927-swisstables
  2. https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h
  3. https://www.youtube.com/watch?v=ncHmEUmJZf4

mockall

Mock object library.

https://crates.io/crates/mockall

quote

Turns rust syntax tree into tokens of rust source code. This is useful in writing proc macros.

https://crates.io/crates/quote

rand

Generate random numbers.

https://crates.io/crates/rand

reqwest

HTTP client library.

https://crates.io/crates/reqwest

syn

Parser for rust source code. This is useful in writing proc macros.

https://crates.io/crates/syn

tokio

Async runtime that drives async tasks to completion.

https://crates.io/crates/tokio

By category

Async programming

  1. futures
  2. reqwest
  3. tokio

Command line arguments

  1. clap

Data structures

  1. hashbrown (port of swisstable)

Testing

  1. mockall

Writing macros

  1. syn and quote