The Ubuntu Search Engine is a project that aims to integrate in only one place all the information and resources available through the Ubuntu Community.
It is a Google Custom Search Engine optimized to finds into all official Ubuntu Linux resources, such as:
The great thing about the Ubuntu Search Engine is that you can filter and refine your search using preconfigured labels that allows you to find what you want in the correct place. For example, you can search for nvidia in all the resources, but you also can filter to search only in the Forums or perhaps only in the Official Documentantion, you can use the filter you want, chosing between the resources mentioned above.
The Ubuntu Search Engine is not related or associated with Canonical Ltd. or Google Inc., it only makes use of the resources made freely available by them.