"However, writing software without defects is not sufficient. In my experience, it is at least as difficult to write software that is safe - that is, software that behaves reasonably under adverse conditions"

This quote by Wietse Venema speaks with the difficulty of writing software application that is not only devoid of defects, but also safe. Writing software without problems is an uphill struggle in itself, however composing software that is safe is an even greater obstacle. Composing software that is safe means that it need to be able to handle unexpected or unfavorable conditions without causing harm or interruption. This needs a great deal of foresight and planning, as well as an extensive understanding of the software application and its environment. Composing software application that is safe is an uphill struggle, however it is necessary for making sure the security and dependability of the software. Without it, software can be vulnerable to destructive attacks or unanticipated mistakes, which can result in severe repercussions.