I made an arcade cabinet frontend that I'd like to share with you.
What's unique about this frontend is that the frontend itself is a video game. It supports MAME and any other program that you can launch from the command line. It's free, of course, and the source code is available on request. It also comes with a powerful configuration utility that lets you easily manage multiple game lists. Unlike most slow and chunky frontends, it boots almost instantly, and you can navigate through the games extremely quickly. It runs extremely smoothly, too. It'll run at whatever refresh rate your display can do (30hz through 144hz). It supports any resolution from 320x240 to 3840x2160, so it'll work on a 15khz arcade monitor in progressive mode all the way through the latest 4k LCD monitor. It supports 4:3 and widescreen aspect ratios, 4:3 letterboxing for widescreen displays, and it supports rotation for vertically oriented monitors.
It even uses a pixel shader to change the graphics during different times of day based on your computer's clock.
--Incito edit --
Link Approved and added in