More than one is great—but ideally we'd have at least one which has reached a level of completeness, stability, desirability etc. to be a sort of standard peopl

More than one is great—but ideally we'd have at least one which has reached a level of completeness, stability, desirability etc. to be a sort of standard people are happy with (again more than one such standard would be great). So if the tradeoff is completing a small amount or starting a larger amount, I'd rather have the small number of more complete options. I guess if you're already happy with VRML, you're set though ;)