Native JavaScript function to get all *text* nodes contained in a selection object.

getTextNodesBetween.js

// Get all *text* nodes contained in a selection object.
// Adapted from code by Tim Down.
// http://stackoverflow.com/questions/4398526/how-can-i-find-all-text-nodes-between-to-element-nodes-with-javascript-jquery
function getTextNodesBetween(selection) {
  var range = selection.getRangeAt(0), rootNode = range.commonAncestorContainer,
      startNode = range.startContainer, endNode = range.endContainer,
      startOffset = range.startOffset, endOffset = range.endOffset,
      pastStartNode = false, reachedEndNode = false, textNodes = [];
  function getTextNodes(node) {
    var val = node.nodeValue;
    if(node == startNode && node == endNode && node !== rootNode) {
      if(val) textNodes.push(val.substring(startOffset, endOffset));
      pastStartNode = reachedEndNode = true;
    } else if(node == startNode) {
      if(val) textNodes.push(val.substring(startOffset));
      pastStartNode = true;
    } else if(node == endNode) {
      if(val) textNodes.push(val.substring(0, endOffset));
      reachedEndNode = true;
    } else if(node.nodeType == 3) {
      if(val && pastStartNode && !reachedEndNode && !/^\s*$/.test(val)) {
        textNodes.push(val);
      }
    }
    for(var i = 0, len = node.childNodes.length; !reachedEndNode && i < len; ++i) {
      getTextNodes(node.childNodes[i]);
    }
  }
  getTextNodes(rootNode);
  return textNodes;
}

// Lazy Range object detection.
function isRange(obj) {
  return ('type' in obj && obj.type === 'Range');
}

// Good-enough Range object comparison.
function rangeChange(data1, data2) {
  return (data1.type !== data2.type || data1.focusNode !== data2.focusNode || data1.focusOffset !== data2.focusOffset);
}

This doesn't get nodes at all, it gets the string contents.