Net::Z3950::SimpleServer is a Perl module which implements the server side of the Z39.50 (information retrieval) protocol. It hides the complexity of network exchanges, packet serialization, and session handling. You are required only to implement simple callbacks to support searching and record retrieval. It is the basis of the "Zoogle" project, which is a Z39.50 gateway to the Google web index.
Java Search Engine is a server-side search engine program for Web sites written completely in Java. It features HTML and PDF indexing, a built-in Web crawler, international encodings support, words and phrases search, and returning results as quotations with highlighted words (like Google). It is available as EJB, JSP, servlet, or Java API library. For non-Java enviroments, it is available as an XML server with XSLT support.
The Multivalent PDF Tools is a suite of tools for manipulating PDF documents. It includes tools for compressing, uncompressing (for hand editing), obtaining metadata, splitting and merging, encrypting and decrypting, validating, imposition (aka n-up), making page images, extracting text, and full-text indexing (with Lucene). The compress tool shrinks the PDF 1.5 Reference from 13.5MB to 8MB in PDF 1.5/Acrobat 6 format and down to 5.1MB in a new proposed "Compact" format.
Dowser is a Web research and archiving tool that clusters results from search engines, associates words that appear in previous searches, and keeps a local cache of all the results you click on in a searchable database along with summaries and links to related information. It helps you to keep track of what you find, with no advertising.