I'm aware on both counts--I was more looking at it from the standpoint of common acceptance. Cassandra was first released in 2008 and became pretty manageable not too long after that. OWA was 1998 and GMail was 2004, but the tools were pretty grungy and hard to get into for awhile. I'd say that they didn't become really legitimately decent until Backbone (late 2010), but there were workable ones for a couple years before that.