TallStreet.com is a new search engine concept where users make investments, with fictional money, in their favourite websites and the rankings are determined entirely by the users.
A big "How to build your own search engine", accompanied by the code of the search engine itself. All of this in French.
Camelserv aspires to be a commercial-quality web server that is 100% written in Perl. It is very easily extensible, and considering the fact that it is written in Perl, it will be pretty much platform-independent.
mnoGoSearch is a full-featured search engine software for intranet and internet servers. It uses SQL databases to store its data and is able to scale index on up to several dozens computers allowing to index up to hundreds millions documents.