I'm looking to develop a CMS project based on UMBRACO but I also need to index the documents created and to offer search functionality therefore I would like to know if you have any suggestion for a lightweight search engine available in .net technology. The main requirement is to be simple and efficient (nothing complex like solr or sphinx ).
If you only need to search documents/nodes created in umbraco you can use xsltsearch perhaps? It's very easy to deploy.