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.
A person may be considered disabled if he or she has a condition that affects the ability to function without assistance at a level needed to maintain well-being. The word disability is also used to refer to a number of federal and state programs that provide assistance to those who are disabled. The two most common programs that fall under the umbrella of disability are Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI).