There’s been a ton of work on Swish3 in the last year. I’ve actually started planning a 1.0 release, after 5 years of work.
Lately I’ve been focusing on three things: (1) making the Perl bindings easier to install; (2) indexing of compressed documents; and (3) supporting XInclude of document fragments. The first is accomplished: you can install the entire library via CPAN. The last two are aimed at large doc sets where I want to keep the XML compressed on disk for space reasons, and where I want to re-use subsets of the document collections in building multiple indexes.