Lua_nvim
This interpreter works inherently in a pseudo-REPL mode and this can’t be disabled. However, it is run within neovim so you can expect the usual vim API functions to be available.
Essentially, you can expect REPL behavior when running line-by-line of bloc-by-bloc lua script:
a = 4
b = 6
print(a+5) -- <- 9
a = 0
print(a + b) -- <- 6