Same jar; different names. xmlParserAPIs.jar hasn't existed for years. See the mailing list archives  for the reasons why.
XML Parser Development
IBM Toronto Lab
Richard <firstname.lastname@example.org> wrote on 02/17/2009 03:22:04 AM:
> Finnaly i reach here.
> when processing xml, i find in my lib directory, there are xml-apis.
> jar and xmlParserAPIs.jar.
> after comparing, i find that they are the same except different names.