The collaborative browser based IDE - Replit Use our free, collaborative, in-browser IDE to code in 50+ languages — without spending a second on setup.

• https://replit.com/

Clojure, Haskell, Kotlin, QBasic, Forth, LOLCODE, BrainF, Emoticon, Bloop, Unlambda, CoffeeScript, Scheme, APL, Lua, Ruby, Roy, Python, Node.js, JavaScript, Deno (beta), Golang, C++, C, C#, F#, HTML, CSS, JS, Rust, Swift, Python (with Turtle), Basic (beta), R, Bash, Crystal, Julia, Elixir, Nim, Dart, Reason Node.js, Tcl, Erlang, TypeScript, Pygame, Love2D, Emacs Lisp (Elisp), PHP Web Server, SQLite, Java, PHP CLI, Pyxel, Raku, Scala (beta), Nix (beta), Kaboom (beta)

.NET language playground

• https://sharplab.io/

• https://github.com/ashmind/SharpLab

Json2CSharp Toolkit

• https://json2csharp.com/

Playground

• https://play.rust-lang.org/

The Go Playground

• https://play.golang.org/

Colaboratory（Colab）Python サービス

• https://colab.research.google.com/

HTML, CSS, JavaScript

• https://codepen.io

Collaborative JavaScript Debugging

• https://jsbin.com/?html,output

Online LaTeX formula editor and browser-based math equation editor

• https://www.hostmath.com/

• https://www.hostmath.com/Demo.aspx

regex101: build, test, and debug regex

QUICK REFERENCEが便利

• https://regex101.com/　

RegExr: Learn, Build, and Test RegEx

• https://regexr.com/

Test code in 250+ PHP versions

• https://3v4l.org/

image compression web app

• https://squoosh.app/

日本語 音声読み上げソフト

• https://ondoku3.com/ja/

• https://github.com/styfle/awesome-online-ide

• https://github.com/hql287/awesome-free-services