https://github.com/alttpo/alttpo - A Link To The Past Online. Lets multiple players see and interact with one another in the same game world and synchronize their progress through the game. Exclusive to a customized fork of the bsnes emulator which provides a scripting language and PPU-integrated drawing routines to render remote player sprites. In retrospect, I consider this a dead-end architecture; redesigned in o2 project (see below).
https://github.com/alttpo/o2 - Second version of alttpo (see above) but this time targeted at SNES hardware console support (via SD2SNES flash cart USB feature) and does not require a customized emulator nor a scripting language. Trade-off here is a loss of the visual aspect (cannot see remote player sprites) due to tight hardware limitations in the amount of VRAM and limited SNES CPU cycles available. Work is in progress to gain back the remote sprite rendering as an optional add-on via the bsnes-plus WASM module support (see below). This project includes a 65816 machine code emitter library (pure Go) with support for named labels of branch targets. There is also a bare-bones headless SNES emulator library (pure Go) included for unit tests to verify the generated 65816 ASM and ROM patching mechanism.
https://github.com/alttpo/bsnes-plus - A fork of bsnes-plus in development that invokes WebAssembly modules when certain general SNES events occur, e.g. `on_nmi`, `on_power`, `on_reset`, `on_frame_present`. WASM code has access to a draw-list API for drawing into the various PPU layers, e.g. extra sprites, text (with PCF font support), basic shapes. WASM code can also receive arbitrary binary messages from external applications, e.g. to update remote player positions or exchange custom sprite graphics.