I would like to ask if it is possible to develop my own XHTML namespace similar to Facebook FBML.
I want to have different tags for displaying boards (similar to fb:board), internalization tags (similar to fb:intl) and more.
Any starting guide/points will be appreciated. Thanks in advance.
No, there is only one XHTML namespace.
That’s an XML namespace, and yes you can.
Namespaces are a W3C recommendation