Remove empty <ul> nodes from IXMLDOMDOCUMENT in Delphi

You can use a simple recursion. Here is an example how:

procedure ScanAndRemove(aNode: IXMLNode);
var
  i: Integer;
  childNode: IXMLNode;
begin
  i := 0;
  while i < aNode.ChildNodes.Count do
  begin
    childNode := aNode.ChildNodes[i];
    if (childNode.NodeName = 'ul') and (childNode.ChildNodes.Count = 0) then
      aNode.ChildNodes.Remove(childNode) else
      begin
        ScanAndRemove(childNode);
        Inc(i);
      end;
  end;
end;

And just pass the document root element:

procedure Cleanup;
var
  xmlDoc: IXMLDocument;
begin
  xmlDoc := TXMLDocument.Create(nil);
  try
    xmlDoc.LoadFromXML('...');
    ScanAndRemove(xmlDoc.DocumentElement);
    // now xmlDoc contains the desired result
  finally
    xmlDoc := nil;
  end;
end;

EDIT The recursive function will remove a node without children, but containing a value. Eg:

<ul>
  blabla
</ul>

If you want the opposite, you should add one more check - ie:

if (childNode.NodeName = 'ul') and 
  (childNode.ChildNodes.Count = 0) and 
  (VarToStrDef(childNode.NodeValue, '') = '') then
  ... 

Or this way - https://stackoverflow.com/a/9673869/3962893