Newbie: Looking for XML/XSD/RelaxNG OSS Editor

Dear all,

This newbie with very little XML experience but big plans is looking for a
Linux XML editor that will support aided XML Schema creation and aided XML
Schema dependent XML File creation (would accept the same RelaxNG based as
well). I have had a trial look at oxygen and like what I saw, but prefer
something OSS.
I'd appreciate if anybody could help.

Joh