You may need to refine your question a bit...
Almost any interchangeable lens made for a 35mm film camera will work on m4/3. As long as an adapter for that lensmount exists, most lenses in that lensmount can be used. We could even broaden that to medium format and micro format (half-frame, 110, Super 8, etc).
Most lenses made for Canon, Contax, EOS, Leica, M42, Maxxum, Minolta, Nikon, Olympus and Pentax-K 35mm SLRs (the most common brands) will work on m4/3. There may be adapters for the less-common SLR mounts as well: Alpa, Exakta, Miranda, Topcon, etc? Most lenses in Leica threadmount or Leica m-mount, or adaptable to Leica mount, will work.
So most everything on the planet will work. Are you looking for something more specific? Are you asking about other ultrafast 50mm lenses like the Noctilux? Other Leica rf lenses? Something else?