Roadmap

Everything that is planned or known to be missing, in one place. What already shipped is in the CHANGELOG; larger items have a design document in design/ with the details and a phased plan.

Nothing here is promised or scheduled. ABI additions keep GASM_ABI_VERSION at 0 (older runners trap only if a guest calls something they lack, see Versioning); breaking changes would bump it.

Next up

The suggested order, from the most benefit for the least risk:

Done recently: stack switching (gasm_run, design/stack-switching.md), cooperative threads in C, POSIX and SDL 3 (design/threads.md) and gasm:gl in the browser and headless (design/gasm-gl.md).

1. gasm:gl natively. ANGLE in gasm-run's window (phase 3 of the plan): mostly building and shipping ANGLE for macOS, Windows and Linux. Then the Rust glow backend, then a Godot port.

Runtime and ABI

Item	What it gives	Status
Cooperative threads in Rust	gasm::thread::spawn and locks on the same scheduler (the C API, POSIX threads and SDL threads are done: design/threads.md, part A). std::thread on wasm32-unknown-unknown can't be redirected.	not started
Stack switching beyond JSPI	Browsers without JSPI (and Node 22) still need the Asyncify builds; wasm's stack-switching proposal would cover them too.	waiting on engines
Real wasm threads	Shared memory and atomics, opt-in, for guests that need parallel CPU (physics, job systems, Godot's worker pool). Not deterministic.	proposal, after cooperative threads: design/threads.md (part B)
Guest memory limit	A cap on linear memory growth. Today a guest can grow to the engine maximum (4 GiB for wasm32); needed before running untrusted content.	not started
Capabilities manifest	Custom section gasm.manifest declaring required and optional imports, network hosts and platform extensions (gasm:ext/*), so runners can check a game before running it.	not started
.gasm packages	One file bundling game.wasm, its assets and a manifest.	not started
gasm:files	A file picker run by the runner: the game only sees what the player picks.	not started
WIT / Component Model	Move the ABI to WIT once browsers don't need transpiling for components.	waiting on browsers

Graphics

Item	What it gives	Status
gasm:gl natively	OpenGL ES 3.0 in gasm-run's window through ANGLE (Metal, D3D11, Vulkan). The ABI, the browser runner (WebGL 2), the null GL of headless runs and the C headers are done; the native window refuses gasm:gl games until then.	next: design/gasm-gl.md, phase 3
gasm:gl in Worker mode	WebGL 2 on a transferred OffscreenCanvas; gasm:gl games run on the main thread for now.	not started
gasm:gl for Rust	A glow::HasContext implementation over gasm::sys::gl_* (egui_glow and other glow code).	not started
Godot	A platform/gasm port on gasm:gl.	after native gasm:gl
gasm:gfx render targets	Render-to-texture.	not started
gasm:gfx cube maps, render bundles	Skyboxes and environment maps; cheaper repeated draws.	not started
Batched gfx commands	One call per frame for draw-heavy guests instead of one per command.	not started
More of WebGPU	Storage textures, compute, stencil: not in the gasm:gfx subset and not planned yet.	not planned

Presentation (2D frames)

The filters, integer scaling, display aspect and window titles shipped in 0.6.0 (design/presentation.md). Left over:

Item	What it gives	Status
mmpx, scalefx filters	More pixel-art upscalers. xbr covers the same content; both need porting from their reference sources, and ScaleFX's license needs checking.	declined for now
Content hint	A guest suggests a filter class ("pixel art" or "rendered") so players can pick a better default. One more small ABI addition.	idea
fps counter behind a flag	The native window title shows — <n> fps always.	idea

Netplay

Item	What it gives	Status
Rollback netplay	Run by the runner: snapshot and restore guest memory between frames (the runner already drives frames and owns the guest's state), instead of lockstep only.	not started

Games and ports

SDL 3

What SDL 3 for gasm doesn't do yet, and what would bring it:

Missing	What it takes
OpenGL, Vulkan, SDL_GPU	gasm:gl (above) for OpenGL ES
Audio recording, camera, haptics and rumble, sensors, dialogs, tray, processes, shared objects	not planned; each fails the way SDL fails on a platform without it

ScummVM

What works is in the ScummVM README. Not done yet:

Missing	Effect	What it takes
Other engines	only the five built in: scumm, scumm_7_8, he, sky, drascula	add them to SCUMMVM_ENGINES (+ engine data); the freeware Flight of the Amazon Queen (queen) and Lure of the Temptress (lure) are next, then Sierra (agi, sci), kyra, gob, saga, sword1/sword2, tinsel
MT-32 emulation	Roland MT-32 music (many Sierra and LucasArts games sound best with it)	--enable-mt32emu (built into ScummVM) and the user's MT-32 ROMs as assets
General MIDI synth (FluidSynth/fluidlite)	GM music; AdLib is used instead	build fluidlite, ship or load a SoundFont
GUI themes	the built-in classic look ("scummremastered" and gui-icons.dat aren't embedded)	embed the theme zip and icons (zlib is in now)
Translations, TTS, FreeType, fribidi	English GUI, no speech synthesis, no TrueType fonts (some engines need them)	build the libraries, embed translations.dat
Video codecs (MPEG-2, Theora, VPX, AAC, JPEG, PNG)	cutscenes and images in engines that use them	build the libraries
3D engines (Grim Fandango, Myst III, The Longest Journey)	not built	TinyGL (software 3D) now, or gasm:gl later
Cloud, LAN, networking	off	gasm:net could carry some of it
Gamepads 2–4, touch controls, virtual keyboard	one gamepad; mouse and keyboard otherwise	backend work
Size in browsers without JSPI	they need the 16.1 MB Asyncify build (the run build is 10.6 MB)	JSPI in more browsers

Godot

A platform/gasm port on gasm:gl: headless first, then the Compatibility renderer. Phase 5 of the gasm:gl plan, its own project.

Testing and tooling

Item	What it gives	Status
Filter parity in CI	scripts/present-test.mjs (native vs WebGL 2 filters, golden images) skips without a GPU; CI's Linux runner would need a software Vulkan driver (lavapipe).	not started