CATEGORY
No standard library::No dynamic allocation 1,340 crates
Data as of 2026-07-25 (crates.io database dump, timestamp 2026-07-25T02:00:36Z). Source: crates.io · db-dump.tar.gz · methodology & corrections.
itertoolsExtra iterator adaptors, iterator methods, free functions, and macros.1,295,966,075MIT OR Apache-2.0
serdeA generic serialization/deserialization framework1,194,795,261MIT OR Apache-2.0
unicode-identDetermine whether characters have the XID_Start or XID_Continue properties according to Unicode Standard Annex #311,162,007,749(MIT OR Apache-2.0) AND Unicode-3.0
itoaFast integer primitive to string conversion1,138,676,266MIT OR Apache-2.0
serde_deriveMacros 1.1 implementation of #[derive(Serialize, Deserialize)]1,125,192,024MIT OR Apache-2.0
ryuFast floating point to string conversion983,998,355Apache-2.0 OR BSL-1.0
pin-project-liteA lightweight version of pin-project written with declarative macros.871,467,017Apache-2.0 OR MIT
zerocopyZerocopy makes zero-cost memory manipulation effortless. We write "unsafe" so you don't have to.750,061,393BSD-2-Clause OR Apache-2.0 OR MIT
unicode-widthDetermine displayed width of `char` and `str` types
according to Unicode Standard Annex #11 rules.699,255,228MIT OR Apache-2.0
rustversionConditional compilation according to rustc compiler version632,840,822MIT OR Apache-2.0
pin-project-internalImplementation detail of the `pin-project` crate.512,479,731Apache-2.0 OR MIT
pin-projectA crate for safe and ergonomic pin-projection.512,437,141Apache-2.0 OR MIT
pasteMacros for all your token pasting needs456,006,342MIT OR Apache-2.0
num-conv`num_conv` is a crate to convert between integer types without using `as` casts. This provides
better certainty when refactoring,…453,211,964MIT OR Apache-2.0
powerfmt`powerfmt` is a library that provides utilities for formatting values. This crate makes it
significantly easier to support…451,445,990MIT OR Apache-2.0
serde_coreSerde traits only, with no support for derive -- use the `serde` crate instead397,642,863MIT OR Apache-2.0
portable-atomicPortable atomic types including support for 128-bit atomics, atomic float, etc.365,896,463Apache-2.0 OR MIT
serde_withCustom de/serialization functions for Rust's serde311,947,588MIT OR Apache-2.0
indocIndented document literals283,041,637MIT OR Apache-2.0
zmijA double-to-string conversion algorithm based on Schubfach and xjb268,034,320MIT
serde_reprDerive Serialize and Deserialize that delegates to the underlying repr of a C-like enum.234,323,777MIT OR Apache-2.0
ref-castSafely cast &T to &U where the struct U contains a single field of type T.188,623,814MIT OR Apache-2.0
serde_bytesOptimized handling of `&[u8]` and `Vec<u8>` for Serde177,263,689MIT OR Apache-2.0
ctorGlobal, no_std-compatible constructors for all platforms that run before main (like C/C++ __attribute__((constructor)))162,228,606Apache-2.0 OR MIT
raw-cpuidA library to parse the x86 CPUID instruction, written in rust with no external dependencies. The implementation closely resembles…146,746,262MIT
unicode-propertiesQuery character Unicode properties according to
UAX #44 and UTR #51.146,129,787MIT/Apache-2.0
owo-colorsZero-allocation terminal colors that'll make people go owo142,792,110MIT
ptr_metaA radioactive stabilization of the ptr_meta rfc140,727,569MIT
ptr_meta_deriveProc macros for ptr_meta140,719,945MIT
rkyvZero-copy deserialization framework for Rust133,142,409MIT
rkyv_deriveDerive macro for rkyv133,125,287MIT
dtoaFast floating point primitive to string conversion131,956,274MIT OR Apache-2.0
bytecheckMemory validation framework for Rust123,436,445MIT
bytecheck_deriveDerive macro for bytecheck123,433,944MIT
typeidConst TypeId and non-'static TypeId112,942,524MIT OR Apache-2.0
inventoryTyped distributed plugin registration106,663,400MIT OR Apache-2.0
seq-macroMacro to repeat sequentially indexed copies of a fragment of code.91,908,860MIT OR Apache-2.0
xxhash-rustImplementation of xxhash83,988,130BSL-1.0
leb128fmtA library to encode and decode LEB128 compressed integers.82,213,843MIT OR Apache-2.0
link-cplusplusLink libstdc++ or libc++ automatically or manually70,354,932MIT OR Apache-2.0
const_fnA lightweight attribute for easy generation of const functions with conditional compilations.62,326,584Apache-2.0 OR MIT
pasteyMacros for all your token pasting needs. Successor of paste.46,150,727MIT OR Apache-2.0
bonNext-gen compile-time-checked builder generator, named function's arguments, and more!44,769,236MIT OR Apache-2.0
dtorGlobal, no_std-compatible destructors for all platforms that run after main (like C/C++ __attribute__((destructor)))37,031,487Apache-2.0 OR MIT
inherentMake trait methods callable without the trait in scope33,218,253MIT OR Apache-2.0
unicode-id-startDetermine whether characters have the ID_Start or ID_Continue properties according to Unicode Standard Annex #3129,710,811(MIT OR Apache-2.0) AND Unicode-3.0
enumnConvert number to enum28,484,350MIT OR Apache-2.0
linkmeSafe cross-platform linker shenanigans26,611,986MIT OR Apache-2.0
monostateType that deserializes only from one specific value25,368,348MIT OR Apache-2.0
mungeMacro for custom destructuring24,794,977MIT
munge_macroMacro for custom destructuring24,788,680MIT
askama_escapeHTML escaping, extracted from Askama24,525,565MIT OR Apache-2.0
ryu-jsFast floating point to string conversion, ECMAScript compliant.24,405,034Apache-2.0 OR BSL-1.0
ghostDefine your own PhantomData17,783,147MIT OR Apache-2.0
auto_enumsA library for to allow multiple return types by automatically generated enum.17,644,721Apache-2.0 OR MIT
objc2-exception-helperExternal helper function for catching Objective-C exceptions9,982,256Zlib OR Apache-2.0 OR MIT
numtoaConvert numbers into stack-allocated byte arrays9,922,463MIT OR Apache-2.0
etherparseA library for parsing & writing a bunch of packet based protocols (EthernetII, IPv4, IPv6, UDP, TCP ...).9,465,620MIT OR Apache-2.0
serde-boolSingle value, true or false, boolean deserializers8,247,474MIT OR Apache-2.0
parsenicA simple no-std/no-alloc I/O and parsing crate7,678,899Apache-2.0 OR BSL-1.0 OR MIT
musli-zerocopyRefreshingly simple zero copy primitives by Müsli.6,159,969MIT OR Apache-2.0
musli-zerocopy-macrosMacros for Müsli zero-copy.6,120,010MIT OR Apache-2.0
volatileVolatile wrapper types for raw pointers5,699,339MIT OR Apache-2.0
automodPull in every source file in a directory as a module.5,339,440MIT OR Apache-2.0
asynk-strimLightweight stream generator library5,310,739MIT OR Apache-2.0
stabbyA Stable ABI for Rust with compact sum-types.5,132,372 EPL-2.0 OR Apache-2.0
stabby-abistabby's core ABI, you shouldn't add this crate to your dependencies, only `stabby`.5,131,629 EPL-2.0 OR Apache-2.0
stabby-macrosthe macros that make working with stabby possible, you shouldn't add this crate to your dependencies, only `stabby`.5,129,961 EPL-2.0 OR Apache-2.0
readonlyStruct fields that are made read-only accessible to other modules4,771,557MIT OR Apache-2.0
easy-extA lightweight attribute macro for easily writing extension trait pattern.3,786,167Apache-2.0 OR MIT
deferUtility to defer excecution of code, inspired by go's defer statement.3,704,734MIT/Apache-2.0
link-sectionLink-time initialized slices for Rust, with full support for Linux, macOS, Windows, WASM and many more platforms.3,680,426Apache-2.0 OR MIT
remainCompile-time checks that an enum, struct, or match is written in sorted order.3,578,649MIT OR Apache-2.0
display_full_errorMinimal display formatter for error chains3,402,927MIT
dragonbox_ecmaFast floating point to string conversion conforming to ECMAScript specification3,345,139Apache-2.0 WITH LLVM-exception OR BSL-1.0
specialThe package provides special functions.3,175,667Apache-2.0 OR MIT
claimsAdditional assertion macros for testing.2,985,846Apache-2.0 OR MIT
focacciano_std implementation of Unicode case folding comparisons2,981,779MIT AND Unicode-3.0
rand_mtReference Mersenne Twister random number generators.2,182,967MIT OR Apache-2.0
futures-enum#[derive(Future, Stream, Sink, AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead)] for enums.2,011,655Apache-2.0 OR MIT
uart_16550Simple yet highly configurable low-level driver for 16550 UART devices,
typically known and used as serial ports or COM ports.…1,837,768MIT OR Apache-2.0
rp-binary-infoCode and types for creating Picotool compatible Binary Info metadata1,716,984MIT OR Apache-2.0
rp235x-halA Rust Embedded-HAL impl for the RP235x microcontroller family1,600,563MIT OR Apache-2.0
minimp3-sysRust bindings for the minimp3 library.1,570,776MIT
z3-sysLow-level bindings for the Z3 SMT solver from Microsoft Research1,569,753MIT
croaring-sysRaw bindings to CRoaring1,557,951Apache-2.0
croaringRust wrapper for CRoaring1,549,495Apache-2.0
semihostingSemihosting for AArch64, Arm, RISC-V, LoongArch, MIPS32, MIPS64, and Xtensa.1,241,182Apache-2.0 OR MIT
colorousProfessional color schemes ported from d3-scale-chromatic1,203,462Apache-2.0
h3o-bitLow-level library for H3 indexes' bit twiddling.1,050,337BSD-3-Clause
no-panicAttribute macro to require that the compiler prove a function can't ever panic.967,976MIT OR Apache-2.0
futures-async-stream-macroImplementation detail of the `futures-async-stream` crate.956,435Apache-2.0 OR MIT
futures-async-streamAsync stream for Rust and the futures crate.954,136Apache-2.0 OR MIT
double-ended-peekableAn adapter providing peeking features to double-ended iterators.833,274MIT
moddefMacro for convenient module declaration. Each module can be put in a group, and visibility can be applied to the whole group with…761,626MIT
rp2040-halA Rust Embedded-HAL impl for the rp2040 microcontroller741,315MIT OR Apache-2.0
multiboot2Convenient and safe parsing of Multiboot2 Boot Information (MBI)
structures and the contained information tags. Usable in…721,401MIT/Apache-2.0
coap-messageInterface to CoAP messages706,591MIT OR Apache-2.0
dcv-color-primitivesa library to perform image color model conversion682,843MIT-0
sequential-storageA crate for storing data in flash with minimal erase cycles.610,766MIT OR Apache-2.0
daftStructural diffs of Rust data structures591,844MIT OR Apache-2.0
const-primesWork with prime numbers in const contexts. Prime generation, primality testing, prime counting, and more.590,449MIT OR Apache-2.0
iter-enum#[derive(Iterator, DoubleEndedIterator, ExactSizeIterator, Extend)] for enums.589,357Apache-2.0 OR MIT
lambert_wFast and accurate evaluation of the Lambert W function by the method of T. Fukushima.575,513MIT OR Apache-2.0
audio-codec-algorithmsAudio codec algorithms: A-law, μ-law and IMA ADPCM519,3890BSD OR Apache-2.0
attr_aliasReduce attribute repetition with aliases494,761MIT OR Apache-2.0
any_vecType erased vector. Most operations can be done without type knowledge. Mostly zero overhead.479,679MIT OR Apache-2.0
libswComprehensive stopwatch library475,999MIT OR Apache-2.0
musli-macrosMacros for Müsli.475,800MIT OR Apache-2.0
musliMüsli is a flexible and efficient serialization framework.472,374MIT OR Apache-2.0
multiboot2-commonCommon helpers for the `multiboot2` and `multiboot2-header` crates.456,209MIT/Apache-2.0
dyn-eqTest equality between trait objects452,429MPL-2.0
digit-layoutThis crate provides a unified data type definition across various libraries, efficiently encodes types in a compact layout, thus…439,678MIT
build-contextMake build environment/target information available as constants in normal libraries and binaries.413,333Apache-2.0 OR MIT
cancel-safe-futuresAlternative futures adapters that are more cancellation-aware389,227MIT OR Apache-2.0
minipngTiny PNG decoder with no dependencies367,2780BSD
clatterno_std compatible implementation of Noise protocol framework with Post-Quantum extensions356,028MIT
libsw-coreComprehensive stopwatch library266,944MIT OR Apache-2.0
micropbRust Protobuf library targetting embedded systems and no_std environments264,681MIT OR Apache-2.0
bump-scopeA fast bump allocator that supports allocation scopes / checkpoints. Aka an arena for values of arbitrary types.261,815MIT OR Apache-2.0
musli-coreCore traits and types for the Müsli serialization framework.256,895MIT OR Apache-2.0
micropb-genGenerate Rust module from Protobuf files256,168MIT OR Apache-2.0
partial-defaultProvides PartialDefault, a trait similar to Default but with fewer guarantees253,346AGPL-3.0-only
coap-numbersConstants for the CoAP protocol245,520MIT OR Apache-2.0
consume_on_dropA zero-cost abstraction that allows Drop::drop to consume self by value235,666MIT
c-enumA macro to generate c-like enums.223,667MIT OR Apache-2.0
stak-vmVirtual machines for Stak Scheme219,914MIT
stak-deviceDevices for Stak Scheme216,732MIT
musli-storagePartially upgrade stable format for Müsli suitable for storage.209,847MIT OR Apache-2.0
stakStak Scheme interpreter207,562MIT
stak-compilerStak Scheme bytecode compiler207,512MIT
stak-macroMacros to integrate Stak Scheme204,032MIT
itybityAn itty bitty crate providing bit iterators and bit iterator accessories.203,252MIT OR Apache-2.0
coap-message-utilsUtilities for using coap-message traits200,979MIT OR Apache-2.0
stak-configurationStak Scheme configuration200,081MIT
stak-sacStand-Alone Complex for Stak Scheme191,586MIT
serde_bytes_ngOptimized handling of `[u8; N]`, `&[u8]` and `Vec<u8>` for Serde186,636MIT OR Apache-2.0
generic-ecGeneral elliptic curve cryptography183,007MIT OR Apache-2.0
coap-handlerInterface to CoAP handlers176,654MIT OR Apache-2.0
sha3-utilsSHA-3 utilities175,634BSD-3-Clause
musli-commonCommon utilities shared among Müsli encodings.171,895MIT OR Apache-2.0
coap-message-implementationsImplementations of coap-message traits, and tools for building them171,400MIT OR Apache-2.0
stak-macro-utilMacro utilities for Stak Scheme169,220MIT
lhashMinimal hashing library167,205BSL-1.0
interruptsCross-architecture utilities for temporarily disabling interrupts and signals.160,565MIT OR Apache-2.0
volatile-macroProcedural macros for the volatile crate.156,677MIT OR Apache-2.0
spideroak-cryptoSpiderOak's cryptography library156,369BSD-3-Clause
device-driverA toolkit to write better device drivers, faster155,702MIT OR Apache-2.0
stak-fileFile system for Stak Scheme151,559MIT
coap-handler-implementationsSimple implementations of CoAP handlers149,455MIT OR Apache-2.0
windowed-infinityA data structure representing an infinite sequentially writable u8 vector of which a small view has writes to it preserved. This…147,367MIT OR Apache-2.0
stak-process-contextProcess context for Stak Scheme147,199MIT
endian-numByte-order-aware numeric types.143,808MIT OR Apache-2.0
mitseinStrongly typed APIs for non-empty collections, slices, and iterators.139,567MIT
musli-wireFully upgrade stable format for Müsli suitable for network communication.138,609MIT OR Apache-2.0
memory_addressesUnified virtual and physical address types for the Hermit ecosystem and beyond138,496MIT/Apache-2.0
arm-pl011-uartArm PrimeCell UART (PL011) driver138,391MIT OR Apache-2.0
one-shot-mutexOne-shot locks that panic instead of (dead)locking on contention.135,119MIT OR Apache-2.0
mendeleevList of chemical elements, their isotopes, and their properties134,400MIT OR Apache-2.0
serde_shortDerive Serialize and Deserialize for enum reperesented as C short enum132,446MIT
stak-buildBuild scripts for Stak Scheme130,760MIT
stak-decodeStak Scheme bytecode decoder129,187MIT
stak-utilStak Scheme utilities129,116MIT
stak-compileStak Scheme bytecode compiler127,149MIT
stak-interpretStak Scheme bytecode interpreter125,576MIT
strum-liteLightweight declarative macro for sets of strings.125,116MIT OR Apache-2.0 OR Unlicense OR WTFPL
printf-compatprintf reimplemented in Rust123,838MIT OR Apache-2.0
stak-timeTime library for Stak Scheme123,442MIT
stak-r7rsStak Scheme primitives for R7RS123,087MIT
device-driver-generationCode generation for the `device-driver` crate115,519MIT OR Apache-2.0
device-driver-macrosProc macro implementation for the `device-driver` crate115,240MIT OR Apache-2.0
serde_unit_struct_deriveProc-macro engine for serde_unit_struct114,011MIT OR Apache-2.0
interrupt-mutexA mutex for sharing data with interrupt handlers or signal handlers.113,754MIT OR Apache-2.0
serde_unit_struct(De)serialize a unit struct as its name113,319MIT OR Apache-2.0
atomic-maybe-uninitAtomic operations on potentially uninitialized integers.113,112Apache-2.0 OR MIT
udigestUnambiguously digest structured data110,552MIT OR Apache-2.0
musli-jsonJSON support for Müsli.107,226MIT OR Apache-2.0
iso3166-staticStatic ISO3166 Data106,888Apache-2.0
musli-valueBuffered value support for Müsli.105,209MIT OR Apache-2.0
iso10383-typesISO 10383 Types103,015Apache-2.0
iso4217-staticStatic ISO 4217 Data101,394Apache-2.0
super-seq-macroMacro to repeat a fragment of code based on a RHAI expression100,190MIT OR Apache-2.0
array_traitA generic trait for any array, with item as type and length as const parameter99,249MIT
stable_try_trait_v2A simple stable implementation of the `Try`, `FromResidual`, and `Residual` traits under the `try_trait_v2` feature.97,985Apache-2.0 OR MIT
stak-minifierStak Scheme source code minifier97,687MIT
stak-wasmStak Scheme in WebAssembly96,839MIT
stak-minifier-macroMacros to minify Stak Scheme source codes96,124MIT
musli-descriptiveA fully self-descriptive format for Müsli.95,532MIT OR Apache-2.0
edge-nalHosts a bunch of traits which are not yet available in the embedded-nal-async crate95,318MIT OR Apache-2.0
stak-minifyStak Scheme source code minifier94,929MIT
stak-nativeOptimized primitives of native functions for Stak Scheme94,817MIT
mstakMinimal Stak Scheme interpreter94,605MIT
mstak-interpretMinimal Stak Scheme bytecode interpreter94,141MIT
stak-moduleModules in Stak Scheme93,796MIT
stak-inexactInexact number operations for Stak Scheme92,864MIT
virtio-specDefinitions from the Virtual I/O Device (VIRTIO) specification.92,590MIT OR Apache-2.0
lakers-sharedEDHOC crypto library constants crate88,059BSD-3-Clause
arm-psciArm Power State Coordination Interface (PSCI) library86,670MIT OR Apache-2.0
fuse-abiFUSE device bindings.86,142MIT OR Apache-2.0
stak-profilerProfiling for Stak Scheme85,878MIT