But UNIX was not always deemed so secure as it is today. In the 1980's, when UNIX was still in its infancy, there were several cases of successful attacks. The first large scale events of infection by what came to be known as "virus" or "worms" were devised and launched against UNIX platforms. Some of the older UNIX software were particularly prone to exploitation: sendmail, the "yellow pages" subsystem, several parts of the X Window System, the entire IRC (Internet Relay Chat) suite, and many other pieces of software contained huge security holes that were patched over the course of more than 30 years of work by developers all around the world.