Open Source Software

Krita is intended for digital painting, but its pixel brush presets, indexed color filter and animation timeline make it a capable pixel art tool once configured.

ASCIIFlow is a browser scratchpad for drawing boxes, arrows and labels in plain ASCII, for diagrams that have to live inside a comment or a text file. There is nothing to install and nothing to sign into.

Aseprite exposes a Lua API, and the community maintains large collections of scripts for outlines, palette tricks, exporters and more. This page collects the best known collections.

BambooTracker writes music for the Yamaha YM2608, the FM chip in NEC's PC-8801 and PC-9801 machines, and its relatives. It has a full FM instrument editor alongside the tracker, and exports to the formats those machines and their emulators play.

Bfxr adds new waveforms, filters and a mixer to the sfxr formula, and runs in the browser.

Bitsy is a tiny editor for making small worlds: a few rooms of 8x8 tiles, an avatar that walks around them, and short conversations with the things in them. The limits are the point - there is no scripting to speak of and two colours at a time - and a finished game is a single HTML file.

Blender is the free 3D suite, and it turns up constantly in low-spec work: modelling and texturing low-poly assets, rendering 3D scenes down to a pixel-art sprite sheet, and building the turnarounds that hand-pixelled animation is traced from. Its add-on ecosystem covers most of the rest.

Blockbench models boxy low-poly meshes with pixel textures painted directly on them, plus animation, and exports to game formats.

Bosca Ceoil is aimed squarely at people who have never written music. Everything is on one screen, the instruments are chosen from a list, and the scale and chord helpers make it hard to play a wrong note. Blue is the maintained rebuild of the original, and it runs on desktop and in a browser.

Defold is a small, free 2D engine that builds unusually light games for desktop, web, mobile and consoles from one project. It is scripted in Lua, ships as a single editor with no licence tiers, and its tilemap and sprite handling suit pixel art directly.

FamiTracker writes music for the NES sound chip and its expansions, and exports NSF files that play on real hardware. Community forks (0CC, Dn) continue its development.

FileToVox converts things that are not voxel models into voxel models: meshes, point clouds, heightmaps, images and Minecraft schematics all become MagicaVoxel files. It runs from the command line, which makes it easy to put in a pipeline.

Furnace is an open source tracker that emulates a very long list of sound chips, from the NES and Game Boy to arcade FM, with VGM export and DefleMask compatibility.

GB Studio makes Game Boy and Game Boy Color games with a visual scripting editor and exports ROMs that run on real hardware and on the web.

GBDK-2020 is the maintained fork of the Game Boy Development Kit: a C compiler, libraries and tools targeting the Game Boy, Game Boy Color, Game Gear and more.

GDevelop builds games out of events - conditions and actions picked from a list - rather than code, which makes it a common first engine. It handles tilemaps, 2D lighting, physics and multiplayer, exports to web, desktop and mobile, and the underlying engine is open source.

A multi-purpose image editor designed as a free replacement for Photoshop. It can be configured for pixel art with the pencil tool, indexed mode and nearest neighbour scaling.

GoatTracker writes SID music on modern machines and exports player routines that run on a real C64.

Godot has a dedicated 2D renderer with pixel-snapping, nearest neighbour filtering and viewport scaling options that make low-resolution games straightforward.

Goxel is a free voxel editor with layers, a procedural renderer and unlimited scene size, available on every platform.

GrafX2 was made for DOS and has been ported everywhere since. It has tools no other program does, constraints for retro platforms, and an antiquated interface.

LDtk is a level editor with auto-tiling rules, entity definitions and a clean JSON format with loaders for most engines.

Laigter builds normal maps and other lighting textures from 2D sprites so they can be lit dynamically in a game engine.

LibreSprite continues the last GPL version of Aseprite as a community project. It keeps the familiar layers, animation timeline and palette tools, and adds its own scripting and a browser build.