fixNES vs Nestalgia

fixNES is a free, open-source NES emulator for Windows and Linux. It runs NTSC and PAL .nes ROMs and creates .sav files for games that support saving. FDS and QD titles can run when a FDS BIOS named disksys.rom is placed in the same folder, and NSF music files are supported with track changes on the left and right keys. Files can be opened by drag and drop, command-line argument or from ZIP archives. The project lists support for NES mappers and VRC6, VRC7, FDS, MMC5, N163 and Sunsoft 5B audio expansions. Controls are keyboard-only; Windows users can use joy2key for controller input. The standalone build uses supplied scripts and requires freeglut and openal-soft, while a Makefile supports RetroArch core use. The README says the project is not in its most complete or cleanest state. It is licensed under MIT.

Nestalgia is a work-in-progress emulator for NES and Famicom systems, built in Kotlin for Linux, macOS and Windows. It also emulates Famicom Disk System, Dendy, Vs. System, NSF and NSFe, and lists support for 305 mappers. The emulator includes save states, battery saves, overclocking and cheat codes, along with fullscreen display and screenshots. Audio, video, controller and emulation settings are configurable. More than 20 controllers are supported, including the NES Controller, Zapper, Power Pad and Four Score. The project lists passing CPU, video, audio, mapper and input accuracy tests. Windows, Linux and Mac downloads require Java 21 or newer. The project is free and open source under GPL-3.0, with no plan limits stated. Android is listed with an uncertain “Coming soon...or not :(” status. Developers can add its core library through JitPack using Gradle instructions. Nestalgia implements the emulator but does not include debugging tools.