They chain of classes used to construct and make one single marker in OpenLayers is a bit difficult to follow, but isn’t impossible. There are three main classes in three files:

Markers.js
Layer/Markers.js
Icon.js

That’s why after tracking the code in them I noticed the library’s using appendChild in a line like that:

this.div.appendChild(markerImg);

The problem is that if you’ve a loop with probably hundreds of iterations this is really slow. What I intent to do is to return only the generated code as string, or instead of returning the element, I can return the string. Than concatenate it after the loop’s over.

That will be way faster!