The Origin of Cross-Site Scripting (XSS) - Hacker Etymology

Why is it called "XSS"? Where does it come from and who influenced this type of website vulnerability?

Full Playlist "The History of XSS": https://www.youtube.com/playlist?list=PLhixgUqwRTjyakFK7puB3fHVfXMinqMSi

Hotmail "Attackments": https://web.archive.org/web/19981205221020/http://because-we-can.com/attackments/default.htm
Which freemail services are safe: https://web.archive.org/web/19981207041804/http://because-we-can.com:80/all/compare.htm
Article about XSS: https://web.archive.org/web/19990117001239/http://www.news.com/News/Item/0,4,25792,00.html ; https://web.archive.org/web/19990117001239/http://www.news.com/News/Item/0,4,25792,00.html
Microsoft Press Release: https://web.archive.org/web/19990117001239/http://www.news.com/News/Item/0,4,25792,00.html
Microsoft XSS FAQ: https://web.archive.org/web/19990117001239/http://www.news.com/News/Item/0,4,25792,00.html
CA-2000-02: https://web.archive.org/web/19990117001239/http://www.news.com/News/Item/0,4,25792,00.html

Chapters:
00:00 - Intro and Recap
01:35 - XSS's 10th Birthday
02:51 - Talking to David Ross
03:47 - Cross-frame Security Issues
04:43 - Hotmail ATTACKMENTS
06:40 - Breeding Ground …

cross-site hacker origin scripting xss