! ROT13 - Bookmarklet

rot13.js

javascript: var coding =
   "abcdefghijklmnopqrstuvwxyzabcdefghijklmABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLM";

function rot13(t) {
   for (var r = "", i = 0; i < t.length; i++) {
      character = t.charAt(i);
      position = coding.indexOf(character);
      if (position > -1) character = coding.charAt(position + 13);
      r += character;
   }
   return r;
}
S = window.getSelection();

function t(N) {
   return N.nodeType == N.TEXT_NODE;
}

function r(N) {
   if (t(N)) N.data = rot13(N.data);
}
for (j = 0; j < S.rangeCount; ++j) {
   var g = S.getRangeAt(j),
      e = g.startContainer,
      f = g.endContainer,
      E = g.startOffset,
      F = g.endOffset,
      m = e == f;
   if (!m || !t(e)) {
         q = document.createTreeWalker(
         g.commonAncestorContainer,
         NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_TEXT,
         null,
         false
      );
      q.currentNode = e;
      for (N = q.nextNode(); N && N != f; N = q.nextNode()) r(N);
   }
   if (t(f)) f.splitText(F);
   if (!m) r(f);
   if (t(e)) {
      r((k = e.splitText(E)));
      if (m) f = k;
      e = k;
   }
   if (t(f)) g.setEnd(f, f.data.length);
}
void 0;

// Rotate by 13 places (Concept: https://en.wikipedia.org/wiki/ROT13)
// Low complexity cryptographic algorithm
// Usage: Select text and trigger bookmarklet