Ultimate Golfing Simulator 3000
Ultimate Golfing Simulator 3000 is a family of programming languages designed by User:rdococ.
Semantics
For every brainfuck program, there is a dialect called Ultimate Golfing Simulator 3000(xxx) with the brainfuck program replacing xxx. If the program is non-empty, a syntax error is reported. Otherwise, the particular brainfuck program corresponding to the dialect is executed.
Examples
A cat program written in Ultimate Golfing Simulator 3000(,[.,]):
A Hello World program, written in Ultimate Golfing Simulator 3000(++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.):
An x86 emulator written in a dialect whose name is too long to present here:
As you can see, this language family absolutely dominates code golfing challenges.
Computational Class
Some of the languages in the Ultimate Golfing Simulator 3000 family can simulate a Turing machine and could be considered ℒ-equivalent. But no language is Turing complete on its own as each can only run one program.