Have you ever tried to merge KML map layers together? For some reason, a lot of the free mapping tools don’t have a simple, easy, intuitive way to merge layers together. So, in response, I made kmlmerger.com to hopefully save others hours of needless pain. In my case, I needed to merge my many different KML files into a single layer such that I could use a free tool for creating a heatmaps. I’m curious to hear about others experiences and pain points of working with KML files. Currently, kmlmerger.com doesn’t support KMZ files, but I could be convinced to add that support if enough folks need it.