There are many projects, viewers, tools, and libraries based on MuPDF. The following diagram shows the official projects developed by Artifex.

iOS App Kit example
Android App Kit example
mupdf-android-mini App
mupdf-android-viewer App
iOS App Kit
Android App Kit
mupdf-android-mini lib
mupdf-android-viewer lib
Java Viewer
MuPDF Android Library
Python Bindings
WASM PDF.js
WASM Viewer
Java Bindings
C++ Bindings
mutool run
mutool draw
mutool clean
Core MuPDF
MuPDF Android Library
iOS App Kit
Android App Kit
mupdf-android-mini
mupdf-android-viewer
libmupdf
The C library that is the foundation for everything MuPDF.
mupdf-gl
The viewer application for Linux and Windows.
mupdf-x11
The original viewer application for Linux and Windows.
mutool
The command line tool suite.
Java Bindings
The JNI bindings and Java classes that expose a low-level Java API to the MuPDF library.
Java Desktop Example
A simple viewer application written in Java. It runs on Mac, Linux, and Windows.
WASM Library
A WebAssembly library and simple high-level API.
WASM Viewer
A single HTML page web application using the WASM library to display PDF files in the browser.
WASM PDF.js
A fork of PDF.js that uses MuPDF as a drop-in replacement for the PDF parser and renderer.
mupdf-android-fitz
An Android library that provides the Java bindings for use with Android apps.
mupdf-android-mini lib and app
The "MuPDF mini" app that is on Google Play. This basic viewer is designed to be a tutorial and example for how to create an Android app from scratch using the MuPDF library. It can also be used as-is to provide an Activity that can be used to display PDF files in other Android apps.
mupdf-android-viewer lib and app
The "MuPDF viewer" app that is on Google Play. This viewer has a more polished UI, but as a result is a lot more complicated and difficult to customize and learn from.
MuPDF iOS SDK and Example
A full featured software development kit and example app for iOS.
MuPDF Android SDK and Example
A full featured software development kit and example app for Android.