Search across multiple Plone instances

If you have multiple Plone instances and you would like the search feature to search across the instances instead of only the one you are performing the search in, there is an add-on called PloneRSSSearch and it is available from the following site:

http://ingeniweb.sourceforge.net/Products/PloneRSSSearch/

Another alternative is to use External Site Catalog but it is more general:

http://ingeniweb.sourceforge.net/Products/ExternalSiteCatalog/