RetroArch

RetroArch is a free, open-source and cross-platform frontend for emulators, game engines, video games, media players and other applications. It is the reference implementation of the libretro API, designed to be fast, lightweight, portable and without dependencies. It is licensed under the GNU GPLv3.
RetroArch runs programs converted into dynamic libraries called libretro cores, using several user interfaces such as command-line interface, a few graphical user interfaces (GUI) optimized for gamepads (the most famous one being called XMB, a clone of Sony's XMB), several input, audio and video drivers, plus other sophisticated features like dynamic rate control, audio filters, multi-pass shaders, netplay, gameplay rewinding, cheats, etc.
RetroArch has been ported to many platforms. It can run on several PC operating systems (Windows, macOS, Linux), home consoles (PlayStation 3, Xbox 360, Wii U, etc.), handheld consoles (PlayStation Vita, Nintendo 3DS, etc.), on smartphones (Android, iOS, etc.), single-board computers (Raspberry Pi, ODROID, etc.) and even on web browsers by using the Emscripten compiler.
History.
Formerly known as SSNES, initially based on pseudonymous programmer byuu's "libretro" predecessor "libsnes", it began its development in 2010 with Hans-Kristian "themaister" Arntzen committing the first change on GitHub. It was intended as a replacement to bsnes's Qt-based interface but it grew to support more emulation "cores". On April 21, 2012, SSNES was officially renamed to RetroArch to reflect this change in direction.
RetroArch's version 1.0.0.0 was released on January 11, 2014 and at the time was available on 7 distinct platforms.
On February 16, 2016, RetroArch became one of the first ever applications to implement support for the Vulkan graphics API, having done so on the same day of the API's official release day.
On November 27, 2016, the Libretro Team announced that, alongside Lakka (LibreELEC-based RetroArch operating system), RetroArch would be on the Patreon crowdfunding platform to allow providing bounties for developers who fix specific software bugs and to cover the costs for matchmaking servers.
In December, 2016, GoGames – a company contracted by video game developer and publisher Sega – approached the RetroArch developers with the intention of using their software in their SEGA Forever project but ultimately the cooperation did not come to fruition due to licensing disagreements.
In April, 2018, Input Lag Compensation was added.
The Libretro Team planned to release RetroArch onto Steam as a free download, integrating Steamworks features into the platform in July 2019. It will be the first major dedicated emulation title to be released on the platform.
In August, 2020, someone impersonating a trusted member of the team got access to the buildbot server and the GitHub account for the libretro organization, causing vandalism and server wipes.
In November, 2020, RetroArch in conjunction with a PCSX2 libretro core allowed the Xbox Series X and Series S to emulate the PlayStation 2, something that Sony's own PlayStation 5 could not do at the time.
Features.
Its major features include:
Supported systems.
RetroArch can run any libretro core. While RetroArch is available for many platforms, the availability of a specific core varies per platform.
Below is a non-exhaustive table of which systems are available to RetroArch and what project the core is based on:
Below is a non-exhaustive list of things that don't fit in the list above, such as individual games, libraries, or programming languages.
Reception.
RetroArch has been praised for the number of systems and games it can play under a single interface.
It has been criticized for how difficult it is to configure, due to the extensive number of options available to the user, and at the same time has been praised for the more advanced features it possesses.
On Android, it has been praised for the fact that overlays can be customized, for the expandability of the libretro cores it supports, for its compatibility with several USB and Bluetooth controller peripherals, in addition to the app being free and having no ads.
Tyler Loch, writing for Ars Technica, said that RetroArch's 'Input Lag Compensation' mode is "arguably the biggest improvement to the experience the retro gaming community has yet seen".