The list of awesome programming tools that can simplify and speed up everyday work. If you are looking for a tool then this list for you! Here you can find interesting programming tools that are not well known, but can be very usefull. Feel free to make a contribution.

• CppInsights - Online C++ decopiler and code explorer tool.
• DartPad - DartPad is a free, open-source online editor to help developers learn about Dart and Flutter.
• DotNetFiddle - If you are sick and tired of starting Visual Studio, creating a new project and running it, just to test simple code or try out samples from other developers you can use DotNetFiddle instead.
• Float exposed - Real numbers visualization service.
• Go Playground - The Go Playground is a web service that runs on go.dev's servers. The service receives a Go program, vets, compiles, links, and runs the program inside a sandbox, then returns the output.
• JsFiddle - JsFiddle is a JavaScript, CSS, HTML or CoffeeScript online code editor.
• Ohmlang Editor - Online grammar editor that can visualize and explain your grammar.
• Rust Playground - The Rust Playground allows you to experiment with Rust before you install it locally, or in any other case where you might not have the compiler available.
• Repl.it - Repl.it is a free, collaborative, in-browser IDE to code in 50+ languages — without spending a second on setup.
• Rextester - This site allows to compile on web with varity different languages: from C# to Assembly.
• SharpLab - SharpLab is a .NET code playground that shows intermediate steps and results of code compilation. Some language features are thin wrappers on top of other features -- e.g. using() becomes try/finally. SharpLab allows you to see the code as compiler sees it, and get a better understanding of .NET languages. SharpLab supports three source languages: C#/VB/F#. There are currently three targets for decompilation/disassembly: C#/IL/JIT Asm. You can use "Run" target to execute your code and see the output.
• TryHaxe - The Haxe online playground.
• TryItOnline - TIO is a family of online interpreters for an evergrowing list of practical and recreational programming languages. This services supports ~700 of programming languages.
• Zig Playground - This is a rudimentary online compiler for the Zig programming language.

• {JSON} Placeholder - Free fake API for testing and prototyping.

• QuickType - QuickType is a tool to generate strongly-typed models and serializers from JSON, JSON Schema, TypeScript, and GraphQL queries, making it a breeze to work with JSON type-safely in many programming languages.

• Carbon - Create and share beautiful images of your source code. Start typing or drop a file into the text area to get started.

• Desmos graphic calc - Graphic calculator.
• Desmos scientific calc - Scientific calculator.
• Desmos matrix calc - Matrix calculator.
• Desmos geom tools - Geometry tools.
• GeoGebra - Free digital tools for class activities, graphing, geometry, collaborative whiteboard and more.
• GraphToy - Free web service to visualize graphs.
• Kalk - Kalk is a powerful command line calculator app for developers.

• Graphics related diagrams - Well drawn diagrams are essential in explaining concepts to others but also in improving your own understanding. Topics such as lighting, shadows and BRDF equations are extremely difficult to get across without pretty pictures! Free render diagrams editor can help with it.

• Glyphter - Icon font generator.

#Analysers

• Slidev - Presentation Slides for Developers.

• Herbie - Herbie - a tool that tells you how to rewrite your maths expressions in a way that preserves IEEE 754 precision better.

• Everything - Locate files and folders by name instantly.