The concept of a hacker originated in the 1970s, and began to gradually take shape in the 1980s. It began to be discussed actively in various contexts, particularly in relation with the rise of open-source operating systems such as GNU and Linux in the 1990s until the early 2000s. Subsequently, as the times changed, the qualities that were demanded of reputable programmers changed in a major way. Originally, the programmers' capabilities in terms of writing code were most important, while their sociability was less emphasized. However, as computers became more common among the general public, and their social impact increased, hackers were required to be more socially amenable in various ways. Therefore, a large number of open-source projects introduced codes of conduct.