Hello Hallvard! First of all I have to say that the ExplorerTree control is not built to display other data than EPiServer pages. With this in mind there are three different appoaches to this (or at least as I can see it): 1. Import the data as pages in EPiServer. The pages could then be synchronized with a scheduled job. This could of course not always be the prefered method, especially if you have major amounts of data. It's hard to set a limit on how much you should be able to have in EPiServer without major performance penalties as this depends on the hardware on the machine and the hierarchy of the data. I would say that this approach could be used if you do not have several tens of thousands of items. 2. Create your own logic to fetch and store the items and wrap them inside of PageData-objects. This is what is done when we get search results from index server. You probably also have to inherit from the ExplorerTree-class and override the fetching of your tree structure. 3. In EPiServer 4.60 we will probably use the sitemap-technology introduced in asp.NET 2.0. Here it's possible to add your own providers to be able to list your own tree for each tree node. I would wait for this if I had the option. I hope that this is enough to be able to choose an approach.