Libertarianism is a term used by political philosophies which seek to promote individual liberty and seek to minimize or abolish the state. Libertarianism is the view that each person has the right to live his life in any way he chooses so long as he respects the equal rights of others. Left-libertarianism endorses full self-ownership, but differs on unappropriated natural resources. Left-libertarianism holds that unappropriated natural resources belong to everyone and must be distributed in some egalitarian manner. Right-libertarianism holds that unappropriated natural resources may be appropriated by individuals.
Leonard Read rejected the concepts of left libertarianism and right libertarianism, calling them authoritarian. Libertarian socialism is often used as a synonym for non-individualist anarchism or socialist anarchism, to delineate it from individualist libertarianism. People who do not use "libertarianism" as a synonym for anarchism but use it to refer to individualistic free-market economics 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.
The Encyclopedia of Libertarianism
Libertarianism: A Political Philosophy for Tomorrow.
Real Libertarianism Assessed: Political Theory after Van Parijs.
Liberatio - Hedonistic Libertarianism.