Struts 1 is obsolete; don't use it for anything new. Struts 2 is stable, if that's what you mean, but it isn't anywhere near as widely used as Struts 1 (and is unlikely ever to become as popular, IMO). I'm sure you can find the release dates by searching "struts release notes" or something like that.
Joined: Sep 22, 2009
i found out, struts 1 came in june 2001, and struts2 came in dec 2005.