Adobe Framemaker and XML
This site contains extensive information on Framemaker and XML.
Framemaker and SGML, not so much. But structured authoring in Framemaker has pretty much moved past SGML in favor of the simpler XML for most purposes. SGML is still supported, but realistically, who uses it any more?
XML: Adobe FrameMaker Outputs XML (but how well? Depends on your Framemaker FDK XML export client.)