This package was previously used to provide a number of
features that were useful for typesetting documents with
XeLaTeX. Many of those features have now been incorporated into
the fontspec package and other packages, but the package
persists for backwards compatibility. Nowadays, loading xltxtra
will: load the fontspec, metalogo, and realscripts packages;
redefine \showhyphens so it works correctly; and define two
extra commands: \vfrac and \namedglyph.
