Penpot: The open-source design tool for design and code collaboration

• UpdatedDec 17, 2025
• Clojure

Collection of custom elements that appear hand drawn. Great for wireframes or a fun look.

• UpdatedOct 7, 2023
• TypeScript

The Pencil Project's unique mission is to build a free and opensource tool for making diagrams and GUI prototyping that everyone can use.

• UpdatedSep 10, 2024
• JavaScript

Design and prototype customized UI, interaction, navigation, transition and animation for App Store ready Apps in Interface Builder with IBAnimatable.

• UpdatedFeb 21, 2023
• Swift

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

• UpdatedDec 17, 2025
• TypeScript

🎨 React application prototyping tool for developers and designers 🏗️

• UpdatedDec 8, 2022
• JavaScript

dnd visual editor - mockups and code in one go!

• UpdatedMar 1, 2023
• JavaScript

Turn Python scripts into handouts with Markdown and figures

• UpdatedAug 28, 2021
• Python

DEPRECATED: Multiplatform GUI Prototyping/Wireframing

• UpdatedSep 19, 2018
• JavaScript

Quickly try out any Swift pod or framework in a playground

• UpdatedNov 23, 2020
• Swift

A Ruby DSL for prototyping card games.

• UpdatedFeb 2, 2025
• Ruby

✔️ Mock data for your prototypes and demos. Remote deployments to Zeit now.

• UpdatedMay 31, 2021
• TypeScript

Browser-based MDX editor

• UpdatedSep 1, 2018
• JavaScript

Mmock is an HTTP mocking application for testing and fast prototyping

• UpdatedNov 20, 2025
• Go

Charm: A Framework for Rapidly Prototyping Cryptosystems

• UpdatedJun 22, 2025
• C

🚧 Build web pages with Vuse, the next-gen interactive page builder powered with Vue.js.

• UpdatedDec 8, 2022
• JavaScript

Web based diagramming app that lets you build interactive diagrams and prototypes

• UpdatedDec 16, 2025
• JavaScript

A platform for packaging and launching blockchain infra. Think docker compose for blockchain

• UpdatedDec 17, 2025
• Go

PHONK is a coding playground for new and old Android devices

• UpdatedJul 29, 2023
• Java

IBM TJBot

• UpdatedDec 4, 2025
• JavaScript