Lakka is described as 'is the official Linux distribution of RetroArch and the libretro ecosystem. Each game system is implemented as a libretro core, while the frontend RetroArch takes care of inputs and display' and is an app in the OS & Utilities category. There are more than 10 alternatives to Lakka for a variety of platforms, including Windows, Linux, Raspberry Pi, Android and Mac. The best alternative is RetroArch, which is both free and Open Source. Other great apps like Lakka are SteamOS (Free, Open Source), Retropie (Free, Open Source), Recalbox (Free, Open Source) and LaunchBox (Freemium).
What is RetroArch? RetroArch is a modular multi-system emulator system that is designed to be fast, lightweight, and portable. It has features lacking in some emulators frontends, such as real-time rewinding and game-aware shading. What systems does it play?
RetroPie allows you to turn your Raspberry Pi or PC into a retro-gaming machine. It builds upon Raspbian, EmulationStation, RetroArch and many other projects to enable you to play your favourite classic games with the minimum set-up.
Ludo is an Emulator Frontend able to run retro video games. Ludo does not emulate the consoles itself, but does it through emulator plugins called libretro cores. Libretro cores are well known emulators (like Snes9x or Genesis Plus GX or PCSX) stripped from their user interface.
batocera.linux is an operating system (like Windows 10 and Mac OS) specialized in retrogaming available for your pc and different nano computers like the Raspberry and the Odroids. Note that you must own games you play in order to respect legality.
A front-end or user interface (UI) is the presentation and interaction layer of an app or website. Most modern emulator apps have basic game list UIs that you can interact with using a mouse/keyboard but not a game controller.
BizHawk is a multi-system emulator designed predominantly around the production of Tool Assisted Speedruns (TAS). BizHawk focuses on core accuracy and power user tools while still being an easy-to-use emulator for casual gaming.
RetriX is an emulator front end for UWP, on all the hardware platforms it supports: it serves the same purpose as RetroArch but is built from the ground up to integrate as well as possible with Windows.