What is rx (rx.cloudhead.io)?

rx is a modern, minimalist pixel editor for Linux, macOS, and Windows. It is built for pixel artists and "hackers" who want a small, fast, extensible tool with as little interface as possible, and it is driven by a command system inspired by vi's modal nature rather than by a dense toolbar of buttons. If you want a conventional, menu-heavy pixel editor, rx is probably not the right fit; if you want a lean editor you can configure and extend, it is aimed at you.

What rx is designed for

The stated purpose is to keep the UI out of the way and focus on the work. Instead of exposing every function as a visible control, rx centers on a command system, so the editing workflow is driven by commands and modes rather than by clicking through panels.

It is intended for two overlapping audiences:

• Artists working on pixel art and sprite animation who want control over their workflow.
• Developers / tinkerers who value a small, hackable codebase and want to extend the editor when something isn't built in.

Core design goals

The project lists five goals that explain most of its behavior:

The performance target is worth noting: the project states update and paint time should be less than 8ms at 1920x1080 on commodity hardware. That is a design target, not a guarantee for every machine.

Features

The editor ships with:

• Built-in sprite animation support, with live preview
• Working with multiple files simultaneously
• An extensible command system
• Configuration via a simple text-based language
• HiDPI support and UI scaling
• Undo/redo for any edit
• Animated GIF output
• Multi-brush / synchronous editing
• Brush filtering, also known as "pixel-perfect" mode
• A visual mode for pixel manipulation

For animation work, the combination of live preview, sprite animation support, and animated GIF output covers the common loop of drawing frames, checking them in motion, and exporting a shareable file.

System requirements and platforms

rx currently supports Linux, macOS, and Windows with OpenGL 3.3 or later. The OpenGL requirement is the main compatibility gate to check before installing, especially on older hardware or virtual machines.

How to install it

There are two routes: build from source, or download a pre-built binary.

Install from source

With cargo and cmake installed, run:

cargo install \
  --git https://github.com/cloudhead/rx \
  --tag v0.5.2

This downloads the latest stable release and installs it under ~/.cargo/bin/rx. If you want a different location, use the --root flag, for example /usr/local.

Platform-specific notes from the project:

• macOS: Xcode and the Xcode Command Line Tools are required. Get the latter with xcode-select --install. CMake can be installed with brew install cmake.

Binary releases

Pre-built binaries are offered as an alternative to building from source. At the time of the source material, only Linux binaries were listed, so check the binary releases section for your platform before assuming a pre-built option exists for macOS or Windows.

Where to get help and learn more

• Guide: read it to learn how to use rx.
• Source: browse it to learn how rx works.
• Community: the rx community is on Discord, for sharing work and discussing the editor.

Who should use it — and who shouldn't

rx is a good fit if you:

• Want a minimal editor with a command-driven, modal workflow
• Care about a small dependency footprint and low resource use
• Want to configure the editor in a text-based language and extend it
• Need sprite animation with live preview and GIF export

rx may not suit you if you:

• Prefer a graphical, menu-and-panel interface over commands and modes
• Need a pre-built installer for a platform that only has source builds available
• Are on hardware without OpenGL 3.3 support