In France, Osteopathy is entirely different from conventional medicine and isn't taught in medical schools as it is considered to be unscientific. Also, osteopaths can't prescribe drugs. That being said, it's extremely popular among people who don't trust conventional doctors, or suffer from troubles that conventional medicine is unable to solve.
I don't know about the US medical system, but I'm a bit surprised about comments saying an osteopath is roughly the same thing an MD.
Edit: there's a dedicated page on wikipedia https://en.wikipedia.org/wiki/Osteopathic_medicine_in_the_Un...
> US DO graduates have historically applied for medical licensure in 87 countries outside of the United States, 85 of which provided them with the full scope of medical and surgical practice. The field is distinct from osteopathic practices offered in nations outside of the U.S., whose practitioners are generally not considered part of core medical staff nor of medicine itself.