SinceHTML’sintroductionin1993,web-programmingtechnologieshavebeeninflux,withwebprogrammersusingdifferentversionsofHTMLfordifferentbrowsers.Theconstantchangemadeitdifficultforauthorstowritequalitytextbooksaboutthesubject.Consequently,mostofthebooksweretradebooks,nottextbooks.WithHTML5’s