To understand why Linux has become so popular, it is helpful to know a little bit about its history. The first version of UNIX was originally developed several decades ago and was used primarily as a research operating system in universities.
Usage Note: Disabled is the clear preference in contemporary American English for referring to people having either physical or mental impairments, with the impairments themselves preferably termed disabilities.
1 A disabled person is a person with an impairment who experiences disability. Disability is the result of negative interactions that take place between a. person with an impairment and her or his social environment. Impairment is. thus part of a negative interaction, but it is not the cause of, nor does it justify, disability.