CLucene is a C++ port of Lucene: the high-performance, full-featured text search engine written in Java. CLucene is faster than lucene as it is written in C++.
Lucino is a C-library with some support for reading and writing Apache Lucene-indices. It currently comes with PHP- and Python bindings.
Clucened is a project to build a daemon around CLucene, which is a C++ implementation of the Lucene search engine. This is *not* the CLucene project, but is a separate project to write a generic daemon based on CLucene.
iMeMex is a dataspace management system. iMeMex is a research prototype. The package also provides several useful components for research such as external sorting, B+-trees, inverted indexes, content converters, query operators, and graph indexes.