Curated list of awesome lists
Awesome Crystal
A curated list of awesome Crystal code and resources. Inspired by awesome and awesome-awesomeness.
The goal is to have projects mostly stable and useful for the community.
Search shards at shards.info or follow announcements Crystal [ANN] for more.
Contributions are welcome. Please take a quick look at the contribution guidelines first.
Algorithms and Data structures
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bisect - Inserting values into a sorted array
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blurhash.cr - BlurHash implementation
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crie - Compile-time Trie
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CrOTP - HOTP and TOTP implementation for two factor authentication
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crystal-linked-list - Implementation of Linked List
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crystaledge - A pure Vector Math library
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crystalg - A Generic Algorithm Library
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crystalline - A collection of containers and algorithms
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csuuid - A Chronologically Sortable UUID
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edits.cr - Collection of edit distance algorithms
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fzy - A Crystal port of awesome Fzy project fuzzy finder algorithm
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Goban - A fast and efficient QR Code implementation
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graphlb - Collection of graph datastructure and algorithms
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haversine - An Implementation of the Haversine formula
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kd_tree - An implementation of "K-Dimensional Tree" and "N-Nearest Neighbors"
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ksuid.cr - K-Sortable Globally Unique IDs
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markov - Build Markov Chains and run Markov Processes
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multiset.cr - Implementation of a multiset
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qr-code - QR Code generator
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radix - Radix Tree implementation
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s2_cells - S2 Geometry for spatial indexing
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secure-remote-password - SRP-6a protocol for authentication over an insecure network
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splay_tree_map - Splay Tree implementation that conforms to the Hash ducktype
Blockchain
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Axentro - A custom blockchain platform
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Cocol - A minimal blockchain testbed
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secp256k1.cr - Elliptic curve used in the public-private-key cryptography
C bindings
Caching
CLI Builders
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admiral - A robust DSL for writing command line interfaces
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Athena Console - Allows for the creation of CLI based commands
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clicr - A simple declarative command line interface builder
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clim - Slim command line interface builder
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Cling - A modular, non-macro-based command line interface library
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commander - Command-line interface builder
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Keimeno - A lightweight text user interface library in Crystal
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OptionParser - command-line options processing (Crystal stdlib)
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Phreak - A highly flexible Crystal CLI builder in the style of OptionParser
CLI Utils
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climate - Tiny tool to make your CLI output 🌈 coloured
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coin - Command-line application that performs currency conversion via the Fixer API
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cride - A light CLI text editor/IDE
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git-repository - A git cli wrapper querying and cloning remote repositories with minimal data transfer
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hetzner-k3s - A CLI tool to quickly create and manage Kubernetes clusters in Hetzner Cloud
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lff - Simple and straightforward large files finder utility in command line
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meet - Start a jitsi meeting quickly from the comfort of your command line
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oq - A performant, and portable jq wrapper to facilitate the consumption and output of formats other than JSON; using jq filters to transform the data
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progress_bar.cr - A simple and customizable progress bar
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tablo - A flexible terminal table generator
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tallboy - Generate ASCII character tables with support for spanning cells over multiple columns
Code Analysis and Metrics
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ameba - A static code analysis tool
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linguist.cr - Using multiple ways to find programming language used in files, based on Github's Linguist
Compression
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Crystar - Readers and writers of Tar archive format
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Gzip - readers and writers of gzip format (Crystal stdlib)
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polylines.cr — compression of series of coordinates
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snappy - Snappy compression format reader/writer for Crystal
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Zip - readers and writers of zip format (Crystal stdlib)
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Zlib - readers and writers of zlib format (Crystal stdlib)
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zstd.cr - Bindings for Zstandard compression library
Configuration
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cr-dotenv - Loads .env file
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Envy - Load environment variables from YAML
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envyable - A simple YAML to ENV config loader
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habitat - Type safe configuration for your classes and modules
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totem - Load and parse a configuration in JSON, YAML, dotenv formats
Converters
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base62.cr - Base62 encoder/decoder, well suited for url-shortening
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crunits - Tool for converting units of measure (miles to kilometers, celsius to fahrenheit etc)
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money - Handling money and currency conversion with ease (almost complete port of RubyMoney)
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sass.cr - Compile SASS/SCSS to CSS (libsass binding)
Cryptography
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cmac - Crystal implementation of Cipher-based Message Authentication Code (CMAC)
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ed25519 - the Ed25519 elliptic curve public-key signature system
described in [RFC 8032]
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monocypher.cr - Crystal wrapper for the Monocypher crypto library
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sodium.cr - Crystal wrapper for the libsodium crypto API
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BinData - Binary data parser helper with an ASN.1 parser
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config.cr - Easy to use configuration format parser
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crinder - Class based json renderer
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Crystalizer - (De)serialize any Crystal object; supporting JSON, YAML, and Byte formats out of the box
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CSV - parsing and generating for comma-separated values (Crystal stdlib)
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front_matter.cr - Separates a files front matter from its content
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geoip2.cr - GeoIP2 reader
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HAR - HAR (HTTP Archive) parser
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INI - INI file parser (Crystal stdlib)
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JSON - parsing and generating JSON documents (Crystal stdlib)
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json-schema - convert JSON serializable classes into a JSON Schema representation
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JSON::OnSteroids - handle and mutate JSON document easily
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maxminddb.cr - MaxMindDB reader
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toml.cr - TOML parser
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XML - parsing and generating XML documents (Crystal stdlib)
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YAML - parsing and generating YAML documents (Crystal stdlib)
Data Generators
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faker - A library for generating fake data
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hashids.cr - A library to generate YouTube-like ids from one or many numbers
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prime - A prime number generator
Database Drivers/Clients
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migrate - A simpler database migration tool with transactions
Debugging
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backtracer.cr - Shard aiming to assist with parsing backtraces into a structured form
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debug.cr -
debug!(…)
macro for pp
-style debugging
Dependency Injection
Email
Environment Management
Examples and funny stuff
Framework Components
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Athena Event Dispatcher - A Mediator and Observer pattern event library
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Athena Negotiation - Framework agnostic content negotiation library
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device_detector - Shard for detect device by user agent string
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Exception Page - An exceptional exception page for Crystal web libraries and frameworks
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graphql - Type-safe GraphQL server implementation
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graphql-crystal - GraphQL implementation
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kemal-session - Session handler for Kemal
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mochi - Authentication shard inspired by Devise supporting: Authenticable, Confirmable, Invitable & more
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motion.cr - Object oriented frontend library for Amber
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multi-auth - Standardized multi-provider OAuth2 authentication (inspired by omniauth)
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praetorian - Minimalist authorization library inspired by Pundit
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Shield - Comprehensive security for Lucky framework
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shrine.cr - File Attachment toolkit for Crystal applications. Heavily inspired by Shrine for Ruby
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tourmaline - Telegram bot framework with an API loosely based on telegraf.js
Game Development
GUI Development
HTML Builders
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blueprint - Write reusable and testable HTML templates in plain Crystal
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form_builder.cr - Dead simple HTML form builder for Crystal with built-in support for many popular UI libraries such as Bootstrap
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to_html - The fastest HTML builder engine for Crystal
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Water - A library for writing HTML in plain Crystal
HTML/XML Parsing
HTTP
Image processing
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celestine - Create SVG images using a DSL
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ffmpeg - FFmpeg bindings that works with StumpyPNG to extract frames
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Pluto - A fast and convenient image processing library
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stumpy_png - Read and write PNG images
Implementations/Compilers
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charly - Charly Programming Language
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cltk - A crystal port of the Ruby Language Toolkit
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crisp - Lisp dialect implemented with Crystal
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LinCAS-lang - A programming language for scientific computation
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mint-lang - A refreshing programming language for the front-end web
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myst-lang - A practical, dynamic language designed to be written and understood as easily and efficiently as possible
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novika - A free-form, moldable, interpreted programming language
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runic-lang - In-design toy language
Internationalization
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crystal-i18n - An internationalization library inspired by Ruby-I18n
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i18n.cr - Internationalization shard
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Lens - A multiformat internationalization (i18n) shard for Crystal. Supports Gettext, Ruby YAML, etc.
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Rosetta - A blazing fast internationalization (i18n) library with compile-time key lookup supporting YAML and JSON formats
Logging and monitoring
Machine Learning
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ai4cr - Artificial Intelligence (based on https://github.com/SergioFierens/ai4r)
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Cadmium - NLP library based heavily on natural
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crystal-fann - FANN (Fast Artifical Neural Network) binding
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mxnet.cr - Bindings for MXNet
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shainet - SHAInet (Neural Network in pure crystal)
Markdown/Text Processors
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markd - Yet another markdown parser built for speed, Compliant to CommonMark specification
Misc
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aasm.cr - Easy to use finite state machine for Crystal classes
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any_hash.cr - Recursive Hash with better JSON::Any included
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anyolite - Full mruby interpreter with simple bindings, allowing for easy scripting support in projects
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burocracia.cr - burocracia.cr the dependecyless shard to validate, generate and format Brazilian burocracias such as CPF, CNPJ and CEP
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callbacks - Expressive callbacks module
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circuit_breaker - Implementation of the circuit breaker pattern
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CrSignals - Signals/slots notification library
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crystal-binary_parser - Binary parser
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crystal-web-framework-stars - Web frameworks for Crystal, most starred on Github
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crz - Functional programming library
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defined - macros for conditional compilation based on constant definitions, version requirements, or environment variable settings
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emoji.cr - Emoji library
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gphoto2-web.cr - Web API for libgphoto2
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immutable - Implementation of thread-safe, persistent, immutable collections
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iterm2 - Display images within the terminal using the ITerm2 Inline Images Protocol
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monads - Monad implementation
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observable - Implementation of the observer pattern
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pinger - Ping IP addresses and DNS entries without requiring sudo
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port_midi - Crystal C bindings for the PortMIDI cross-platform MIDI I/O library
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retriable.cr - Simple DSL to retry failed code blocks
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serf-handler.cr - Framework for building Serf handlers, with a suite of useful builtin capabilities
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simple_retry - Simple tool for retrying failed code blocks
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sslscan.cr - Crystal shard wrapping the rbsec/sslscan utility
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version_tools - Version-dependent behaviour, specified at compile-time
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wafalyzer - Web Application Firewall (WAF) Detector - shard + cli
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zaru_crystal - Filename sanitization
Network Protocols
Networking
ORM/ODM Extensions
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avram - A database wrapper for reading, writing, and migrating Postgres databases
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clear - ORM specialized to PostgreSQL only but with advanced features
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crecto - Database wrapper, based on Ecto
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granite - ORM for Postgres, Mysql, Sqlite
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jennifer.cr - Active Record pattern implementation with flexible query chainable builder and migration system
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rethinkdb-orm - ORM for RethinkDB / RebirthDB
Package Management
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shards - Dependency manager for the Crystal
Processes and Threads
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await_async - Add keywords await & async in Crystal Lang
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concurrent.cr - Simplified concurrency using streams/pipelines, waitgroups, semaphores, smores and more
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neph - A modern command line job processor that can execute jobs concurrently
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promise - A Promise implementation with type inference
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werk - Dead simple task runner with concurrent support, ideal for local CI
Project Generators
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crystal_lib - Automatic binding generator for native libraries
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fez - A Kemal application generator
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libgen - Automatic bindings generator configured using JSON/YAML files
Queues and Messaging
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mosquito - Redis backed periodic and ad hoc job processing
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NATS.io - NATS client
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sidekiq.cr - Simple, efficient job processing
Routing
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orion - A minimal, rails-esque routing library
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router.cr - Minimum but powerful http router for HTTP::Server
Scheduling
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crystime - Advanced time, calendar, schedule, and remind library
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schedule.cr - Run periodic tasks
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tasker - A high precision scheduler including timezone aware cron jobs
Science and Data analysis
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alea - Repeatable sampling, CDF and other utilities to work with probability distributions
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ishi - Graph plotting package with a small API and sensible defaults powered by gnuplot
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linalg - Linear algebra library inspired by MATLAB and SciPy.linalg
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num.cr - Numerical computing library supporting N-Dimensional data
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predict.cr - Satellite prediction library using the sgp4 model
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quartz - Modeling and simulation framework
Search
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hermes - Data Mapper pattern implementation for ElastiSearch
Serverless Computing
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crystal_openfaas - Template to enable crystal as first class citizens in OpenFaaS
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secrets-env - Extends ENV module to read values injected by docker / kubernetes secrets and other orchestration tools
System
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baked_file_system - Virtual file system implementation
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hardware - Get CPU, Memory and Network informations of the running OS and its processes
Task management
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cake - Production-ready Make-like utility tool
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sam - Another one Rake-like task manager with namespacing and arguments system
Template Engine
Testing
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Athena Spec - Common/helpful Spec compliant testing utilities
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crotest - A tiny and simple test framework
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crytic - Mutation testing framework
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hashr - A tiny class makes test on JSON response easier
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LuckyFlow - Automated browser tests similar to Capybara
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mass-spec - Web API testing library
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microtest - Small opinionated testing library focusing on power asserts
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minitest.cr - Library for unit tests and assertions
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mocks.cr - Mocking library for Crystal
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Spec - spec framework (Crystal stdlib)
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spectator - Feature rich spec framework that uses the modern expect syntax
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timecop.cr - Library for mocking with
Time.now
. Inspired by the timecop ruby gem
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vcr - A HTTP capture and replay implementation for crystal
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webdriver_pump - Page Object library. Inspired by Ruby's WatirPump
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webmock.cr - Library for stubbing
HTTP::Client
requests
Third-party APIs
Validation
Web Frameworks
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amber - Open source efficient and cohesive web application framework
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Athena - A web framework comprised of reusable, independent components
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grip - The microframework for writing powerful web applications
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kemal - Lightning Fast, Super Simple web framework. Inspired by Sinatra
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lucky - Catch bugs early, forget about most performance issues, and spend more time on code instead of debugging and writing tests
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marten - A web framework that makes building web applications easy, productive, and fun
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runcobo - An api framework with simple, intuitive and consistent DSL, using jbuilder to render json
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Shivneri - Component based MVC web framework for crystal targeting good code structures, modularity & performance
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spider-gazelle - A Rails esque web framework with a focus on speed and extensibility
Unofficial
Resources
Official Documentation Translations
Services and Apps
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carc.in - A web service that runs your code and displays the result
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Crank - A Procfile-based application manager (like Foreman)
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cry - Ability to execute crystal code in a fashion similar to Ruby's pry edit
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Crystal [ANN] - Announce new project, blog post, version update or any other Crystal work
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DeBot - IRC bot written in Crystal
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icr - Interactive console for Crystal (like IRB for Ruby)
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Invidious - Invidious is an alternative front-end to YouTube
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mpngin - A URL shortener with simple stats
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procodile - Run processes in the background (and foreground) on Mac & Linux from a Procfile (for production and/or development environments)
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quicktype - Generate models and serializers from JSON, JSON Schema, GraphQL, and TypeScript
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shards.info - Web service that lists all repositories on GitHub that have Crystal code in them. The sources are available on GitHub
DevOps
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ansible-crystal - Ansible playbook for installing crystal
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DPPM - An easy, universal way to install and manage applications as packages (mostly Linux)
Editor Plugins
- Acme:
- Atom
- Emacs
- Geany
- IntelliJ IDEA
- Lite-XL
- Spacemacs
- Sublime
- TextMate
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Crystal.tmbundle - Crystal syntax highlighting, compile, format command, snippets
- Vim
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vim-crystal - Vim filetype support for Crystal
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vim-slang - Vim filetype support for Slang Templating Engine
- Visual Studio Code
LSP Language Server Protocol Implementations
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crystalline - Crystalline is an implementation of the Language Server Protocol written in and for the Crystal Language
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scry - Code analysis server for Crystal implementing the Language Server Protocol
Shell plugins
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crun - Crystal Run : shebang wrapper for Crystal
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crystal-zsh - .oh-my-zsh plugin