Where is F# Interactive on Mac

Those names are just the Mono script wrappers for fsi.exe and fsc.exe.

They are the same CIL-based "exe" wrapped in a sh script to execute them via the mono runtime. Create some aliases in the shell of choice if you want to.

/Library/Frameworks/Mono.framework/Versions/Current/Commands/fsharpc

#!/bin/sh
EXEC="exec "

if test x"$1" = x--debug; then
   DEBUG=--debug
   shift
fi

if test x"$1" = x--gdb; then
   shift
   EXEC="gdb --eval-command=run --args "
fi

if test x"$1" = x--valgrind; then
  shift
  EXEC="valgrind $VALGRIND_OPTIONS"
fi

# Beware this line must match the regular expression " (\/.*)\/fsi\.exe" when fsc.exe is fsi.exe.
# That's because the FSharp MonoDevelop addin looks inside the text of this script to determine the installation
# location of the default FSharp install in order to find the FSharp compiler binaries (see
# fsharpbinding/MonoDevelop.FSharpBinding/Services/CompilerLocationUtils.fs). That's a pretty unfortunate
# way of finding those binaries. And really should be changed.
$EXEC /Library/Frameworks/Mono.framework/Versions/5.16.0/bin/mono $DEBUG $MONO_OPTIONS /Library/Frameworks/Mono.framework/Versions/5.16.0/lib/mono/fsharp/fsc.exe --exename:$(basename "$0") "$@"

/Library/Frameworks/Mono.framework/Versions/Current/Commands/fsharpi

#!/bin/sh
EXEC="exec "

if test x"$1" = x--debug; then
   DEBUG=--debug
   shift
fi

if test x"$1" = x--gdb; then
   shift
   EXEC="gdb --eval-command=run --args "
fi

if test x"$1" = x--valgrind; then
  shift
  EXEC="valgrind $VALGRIND_OPTIONS"
fi

# Beware this line must match the regular expression " (\/.*)\/fsi\.exe" when fsi.exe is fsi.exe.
# That's because the FSharp MonoDevelop addin looks inside the text of this script to determine the installation
# location of the default FSharp install in order to find the FSharp compiler binaries (see
# fsharpbinding/MonoDevelop.FSharpBinding/Services/CompilerLocationUtils.fs). That's a pretty unfortunate
# way of finding those binaries. And really should be changed.
$EXEC /Library/Frameworks/Mono.framework/Versions/5.16.0/bin/mono $DEBUG $MONO_OPTIONS /Library/Frameworks/Mono.framework/Versions/5.16.0/lib/mono/fsharp/fsi.exe --exename:$(basename "$0") "$@"

In Terminal window, with bash shell:

sudo ln -s /Library/Frameworks/Mono.framework/Versions/Current/Commands/fsharpi /Library/Frameworks/Mono.framework/Versions/Current/Commands/fsi

Then fsi should work. If not, make sure that the directory above is in your PATH: echo $PATH