About the history of the html "meta" tag:
The first major crawler-based search engines to use the meta keywords tag were Infoseek and AltaVista. It's unclear which one provided support first, but both were offering it in early 1996. When Inktomi launched in mid-1996 through the HotBot search engine, it also provided support for the tag. Lycos did the same in mid-1997, taking support up to four out of the seven major crawlers at the time (Excite, WebCrawler and Northern Light did not provide support).
The ascendancy of the tag did not last after 1997. Experience with the tag has showed it to be a spam magnet. Some web site owners would insert misleading words about their pages or use excessive repetition of words in hopes of tricking the crawlers about relevancy. For this reason, Excite (which also owned WebCrawler) resisted added support. Lycos quietly dropped its support of the tag in 1998, and newer search engines such as Google and FAST never added support at all.
. Hmmm, could this mean anything for the Semantic Web?