Right-libertarianism holds that unappropriated natural resources may be appropriated by individuals.
Libertarianism is a term used by political philosophies which seek to promote individual liberty and seek to minimize or abolish the state.
Left-libertarianism endorses full self-ownership, but differs on unappropriated natural resources.
Right-libertarianism holds that unappropriated natural resources may be appropriated by individuals, but Left-libertarianism goes further and holds that unappropriated natural resources belong to everyone and must be distributed in some egalitarian manner.
Leonard Read rejected the concepts of Left-libertarianism and "Right-libertarianism, calling them authoritarianism.
Libertarian socialism is often used as a synonym for non-individualist anarchism or socialist anarchism, to dilineate it from individualist libertarianism.
People who do not use libertarianism as a synonym for anarchism but use it to refer to individualistic free-market philosophy only, refer to free-market anarchism as libertarian anarchism.
Libertarianism is also synonymous with classical liberalism.
The word libertarian is an antonym of authoritarian. Till recently the term libertarianism was often used as a synonym for anarchism.