Our client is owner of a famous discussion forum of Belgium. The forum is based on vBulletin. The search was the main feature used by the users to fine relevant topics. The default vBulletin search was not good and was very slow.
Client reached to us to make the search relevant and faster. We integrated Sphinx Search into forum using a plugin. We customized the Sphinx plugin to improve the relevancy of the results. vBulletin uses a lot of HTML entities to encode the posts specially for not English characters. These entities are not searchable by default but our solution enabled search in those entities.
You can see the search in action here