<p>I invested some time into learning R and would prefer not to learn Python or Ruby just for convenience of parsing XML.</p>

<p>I am not a pro R programmer so I need a higher level library then XML package of R.
getNodeSet and XPath is very hard to use.</p>

One option is <a href="https://github.com/ropensci/rentrez">rentrez</a>, from the <a href="http://ropensci.org/">rOpenSci</a> family of packages.