Is my work in designing websites that may contain sections for songs, chat, or funny video clips—knowing that we do not design pornographic websites—religiously forbidden and a source of ongoing sins?

It is forbidden to design websites that include songs and mixed chat sites that do not adhere to Islamic etiquette, and any design that contains pictures of unveiled women or words that call to vice and transgress the limits of Allah, because that is a sin. Allah Almighty has forbidden cooperation in sin and aggression. Therefore, it is not permissible to work as a designer or developer for such websites, and one must repent and cease from this sin.