On my up-to-date MiKTeX system, there is a copy of
url.sty in three different places in the TDS:
texmf\tex\xelatex\xetexurl(part of MiKTeX package
xetexurl, packaged on 2007-Sep-05)
texmf\tex\latex\url(part of MiKTeX package
url, packaged on 2010-Jan-26)
texmf\tex\latex\ltxmisc(part of MiKTeX package
ltxmisc, packaged on 2012-Dec-20)
The first one (in
xetexurl) is version 3.1; the other two are version 3.3.
Why does the package exist in 3 different locations? Given that this is the case, how does the TeX program know which one to use? It seems that when I run
LuaLaTeX, it chooses the one from
ltxmisc, giving log entry
Package: url 2006/04/12 ver 3.3 Verb mode for urls, etc.
while when running
XeLaTeX it chooses the one from
xetexurl, giving this log entry:
Package: url 2004/03/15 ver 3.1 Verb mode for urls, etc.
Why the discrepancy?