Printer Firmware

Firmware controls the steppers, heaters, and motion planning on the printer itself. In 2026, Klipper has become the default for tinkerers and high-performance machines (Vorons, RatRigs, modded Enders, even many stock Bambu/Prusa converts), while Marlin remains everywhere on entry-level and stock 8-bit boards. See Klipper & Printer Web UIs for the host-side interfaces.

Klipper

• ★ Klipper — open source (GPLv3); host-based firmware (heavy lifting on a Raspberry Pi / SBC, microcontroller is a dumb motion executor). Input shaping, pressure advance, fast async motion, easy macros. The performance-tier default.
• Kalico (formerly Danger-Klipper) — open-source community fork of Klipper with extra experimental features (nonlinear extrusion, faster homing, dockable toolheads). Tracks upstream closely.
• Cartographer / Beacon firmware — Klipper modules for high-speed contact-less bed scanners.

Marlin

• ★ Marlin — open source (GPLv3); the universal microcontroller firmware. Runs on practically every consumer printer. Marlin 2.x supports 32-bit boards; configuration is C++ headers compiled per machine.
• Configurator (marlinfw.org) — web tool to generate Configuration.h / Configuration_adv.h.
• Vendor Marlin forks — Creality, Anycubic, Elegoo, Sovol all ship customized Marlin builds. Often outdated; communities maintain better forks (Professional Firmware, Jyers, etc.).

RepRapFirmware (Duet)

• ★ RepRapFirmware (RRF) — open source (GPLv3); for Duet boards (Duet 3 6HC/6XD/Mini5+) and a few clones (Fly RRF). Excellent multi-tool / IDEX / CNC support, web UI built in (DWC). The pick for high-end DIY motion platforms that want something less DIY-feeling than Klipper.
• Duet Web Control (DWC) — bundled web UI; no separate host computer needed.

Prusa firmware

• Prusa Firmware (Buddy / MK4 / MK3.5/3.9 / XL) — open source (GPLv3 with some closed bootloader pieces); ships on Prusa hardware. Mature, conservative, stable.
• Prusa Mini firmware — same family, smaller MCU.
• Prusa-Slicer / printer integration — telemetry, MMU3 control, input shaping on MK4+.

Bambu / closed-source vendor firmware

• Bambu firmware — closed source; required on stock Bambu printers. Klipper conversions (e.g., X1Plus, OpenBambu) exist but are unofficial.
• X1Plus — community jailbreak for Bambu X1C that opens up the locked-down firmware. Open source, controversial (vendor-hostile).
• Creality / Anycubic / Elegoo stock firmware — generally Marlin-derived; quality varies.

Bootloaders & flashing tools

• Marlin Auto Build (PlatformIO + VSCode) — the standard Marlin compile/flash flow.
• KIAUH — Klipper Installation And Update Helper; bash script to install Klipper + Mainsail/Fluidd/Moonraker on a fresh Pi.
• MainsailOS / FluiddPi / RatOS — pre-baked SBC images with everything installed.
• Kiauh-extended, Crowsnest install scripts — community installers for cameras and add-ons.

Pick this if…

• Best motion performance, willing to learn: Klipper.
• Stock printer, "just works": Marlin (or whatever shipped).
• High-end DIY (IDEX, 5-axis, CNC): RepRapFirmware on a Duet.
• You bought a Prusa: Prusa firmware — don't fight it.
• Bambu X1C and you want it open: X1Plus (with eyes open about risks).