any progress or suggestions on an xslt base64 decoder?

Hello all,

I am attempting to create an xslt document that will translate base64
characters to human-readable floating point text (to support viewing
via a web browser).

I was able to come across this work

http://gandhimukul.tripod.com/base64encoder.xsl
http://gandhimukul.tripod.com/datamap.xml

which looks interesting, but not very well commented or simple.

Has there been any work toward supporting base64 conversion natively
in a future xslt spec?  Any thoughts or suggestions are greatly
appreciated.  Thank you.

Mike Gilbert