whats the most definitive means of establishing the applicable license for any given library
You find the source code of the library, in there, there must be some kind of
COPYING document. That is the "applicable license" for the corresponding library.
You'll find multiple, tons, of software written by parties 3rd to Apache, who use the ALv2. All of those uses are unrequested from the Apache Foundation and the Apache Foundation has no derived responsibility.
If you find that some software is using some license such as the "A" license, you don't go to "A" to check if that's true. Other "A"s here are e.g. MIT, zlib, etc.
Instead use the
guide to find license for software package whatever
Find the library in mvnrepository or wherever: http://mvnrepository.com/artifact/xml-apis/xml-apis/1.4.01.
Jump to the home page: http://xml.apache.org/commons/components/external/ (ask for further help if you don't find this in the page of step 1).
Fetch the Apache XML commons source code: https://xerces.apache.org/xml-commons/
3.1. No luck next time? Derive it via Ohloh: https://www.openhub.net/p/xml-commons, access code locations, only if unbroken at Ohloh.
Keep fetching the source code: http://xerces.apache.org/mirrors.cgi.
Download the thing: http://apache.uvigo.es//xerces/j/source/Xerces-J-src.2.12.0.zip.
Uncompress, find the
LICENSE (sometimes they call it
Version 2.0, January 2004
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
Hope that helped.