OpenLayers is a mapping library that allows Ushahidi to utilize a common set of tools for showing different basemaps, points, geometries, etc. Due to the vast amount of functionality in OpenLayers, we use a custom build that includes only what we need. This reduces the file users have to download from over a megabyte to somewhere between 300-500kb.
OpenLayers comes with a build script that you can run to compile your own version of OpenLayers. Instructions for that can be found in the package you download from the OpenLayers website. If you are hacking on Ushahidi and need additional functionality, you will want to modify the build configuration that we provide with Ushahidi. This config file can be found in /application/config/openlayers.ushahidi.cfg. Simply copy this file and add it to your OpenLayers build directory. This is the file where you will add the additional libraries you need included. Follow the instructions in the OpenLayers build readme to see how to reference this file.
If you do a build using our config file on the default OpenLayers, you will get an error. You must include the Loading Panel Addin before you do the build. You will not see any warnings or errors if you build without it!