RMG v0.5.2 is released. Rosalie's Mupen GUI is a free and open-source mupen64plus GUI written in C++. It offers a simple-to-use user interface.

RMG changelog:
Fix drag and drop not working in the loading screen of the ROM browser
Fix ROM browser not refreshing when launching RMG with a ROM specified through the commandline, using drag and drop and then returning to the ROM browser
Fix ROM browser refreshing with '--quit-after-emulation' specified through the commandline after a ROM has finished executing causing some extra debug callbacks to be displayed
Fix ROMs which have a ROM header name with 20 characters without a 0 byte at the end (fixes a crash on windows)
Improve build process by automatically detecting whether 'std::format' is supported or not (if not, use libfmt)
Improve message box behavior when there are a lot of errors
Improve default directories on windows (it'll now use '%APPDATA%\RMG' unless 'portable.txt' or 'Config\mupen64plus.cfg' exists)

Download: RMG v0.5.2
Source:Here