Additional documentation can be found at the Marlin Home Page. Please test this firmware and let us know if it misbehaves in any way. Volunteers are standing by!

Marlin 2.1 continues to support both 32-bit ARM and 8-bit AVR boards while adding support for up to 9 coordinated axes and to up to 8 extruders.

Download earlier versions of Marlin on the Releases page.

Before building Marlin you'll need to configure it for your specific hardware. Your vendor should have already provided source code with configurations for the installed firmware, but if you ever decide to upgrade you'll need updated configuration files. Marlin users have contributed dozens of tested example configurations to get you started. Visit the MarlinFirmware/Configurations repository to find the right configuration for your hardware.

To build Marlin 2.1 you'll need Arduino IDE 1.8.8 or newer or PlatformIO. Detailed build and install instructions are posted at:

• Installing Marlin (Arduino)
• Installing Marlin (VSCode).

Marlin 2.0 introduced a layer of abstraction to allow all the existing high-level code to be built for 32-bit platforms while still retaining full 8-bit AVR compatibility. Retaining AVR compatibility and a single code-base is important to us, because we want to make sure that features and patches get as much testing and attention as possible, and that all platforms always benefit from the latest improvements.

• Submit Bug Fixes as Pull Requests to the (bugfix-2.1.x) branch.
• Follow the Coding Standards to gain points with the maintainers.
• Please submit your questions and concerns to the Issue Queue.

The Issue Queue is reserved for Bug Reports and Feature Requests. To get help with configuration and troubleshooting, please use the following resources:

• Marlin Documentation - Official Marlin documentation
• Marlin Discord - Discuss issues with Marlin users and developers
• Facebook Group "Marlin Firmware"
• RepRap.org Marlin Forum
• Facebook Group "Marlin Firmware for 3D Printers"
• Marlin Configuration on YouTube

Marlin is constantly improving thanks to a huge number of contributors from all over the world bringing their specialties and talents. Huge thanks are due to all the contributors who regularly patch up bugs, help direct traffic, and basically keep Marlin from falling apart. Marlin's continued existence would not be possible without them.

Regular users can open and close their own issues, but only the administrators can do project-related things like add labels, merge changes, set milestones, and kick trolls. The current Marlin admin team consists of:

• Scott Lahteine [@thinkyhead] - USA - Project Maintainer   💸 Donate
• Roxanne Neufeld [@Roxy-3D] - USA
• Keith Bennett [@thisiskeithb] - USA   💸 Donate
• Peter Ellens [@ellensp] - New Zealand   💸 Donate
• Victor Oliveira [@rhapsodyv] - Brazil
• Chris Pepper [@p3p] - UK
• Jason Smith [@sjasonsmith] - USA
• Luu Lac [@shitcreek] - USA
• Bob Kuhn [@Bob-the-Kuhn] - USA
• Erik van der Zalm [@ErikZalm] - Netherlands   💸 Donate

Marlin is published under the GPL license because we believe in open development. The GPL comes with both rights and obligations. Whether you use Marlin firmware as the driver for your open or closed-source product, you must keep Marlin open, and you must provide your compatible Marlin source code to end users upon request. The most straightforward way to comply with the Marlin license is to make a fork of Marlin on Github, perform your modifications, and direct users to your modified fork.

While we can't prevent the use of this code in products (3D printers, CNC, etc.) that are closed source or crippled by a patent, we would prefer that you choose another firmware or, better yet, make your own.