SE 5.0 final (released on 10.31.2003):
The following JARs:
jaxp-api.jar, xercesImpl.jar, xsltc.jar, xalan.jar, sax.jar, dom.jar
came from the JWSDP 1.3 dated 10/20/2003.
We know that the previous version of JWSDP (v 1.2) had Xerces 2.3.0 inside it, and that's what SE 5.0b1 used.
SE 4.2 final:
Like SE 5.0, it comes with several XML/XSLT JAR files.
But different from SE 5.0... some of these JARs were obtained from Sun's Java XML Pack,
while others were obtained from JWSDP the Java Web Services Developer Pack.
So these are just standard JARs from Sun.
For example, with SE 4.2, the Summer 02_01 Release of the Java XML Pack, and version 1.0 of the JWSDP were used.
These were the most current versions at the time SE 4.2 was released.
As newer versions (not hotfixes) of SE come out, newer versions of these JARs will be included (in favor of the older ones).
To learn more about the version of any particular JAR, you should read the
Meta-Inf\Manifest.mf file contained within the JAR, using a plain text editor.
For the most part, ServletExec only needs a few of these parsing JARs in order to function.
xercesImpl.jar is the Xerces implementation of the interfaces defined in
jaxp-api.jar (those 2 JARs go hand-in-hand).
ServletExec uses the classes in these 2 JARs (or newer, backward compatible versions) in order to parse web.xml files, and TLD files.
The other XML/XSLT JARs are not used unless you run code that needs them.
An example of such code would be if you were to run a Web Service or a Web Service Client inside SE.
Then classes found in JARs such as
xalan.jar, etc... would be needed.
You should be able to upgrade any of these JARs so long as the newer versions are backward compatible.
SE FAQ #382 may also be helpful.