cthumb allows you to create Web albums of digital pictures with thumbnails, captions, and several different views of the collection, including (optionally) several languages and resolutions. An album is composed of a series of pages, each composed of a collection of pictures. You can have several annotations per picture, and can customize almost everything in the way the albums look on the screen.
Enzyme is an architecture for creating user-searching-user applications. Right now, it is primarily useful as a resume create/search and HR management system. However, it's potential uses are wide-ranging, and it offers PHP developers an alternative to relying on simple "keyword" searching systems.
eXist is a native XML database featuring efficient, index-based XPath query processing, extensions for keyword search, XUpdate support, and tight integration with existing XML development tools. The database is lightweight and may be easily deployed in a number of ways, running either as a stand-alone server process, inside a servlet engine, or directly embedded into an application.
mp3riot (formerly known as f2html.pl) is a command line utility that searches recursively through directories, builds a file list (with additional file information), and generates HTML files, playlists, etc. The output can be controlled, links can be corrected, and more. The script is mainly desigend to create Web pages, playlists, and databases for MP3 and Ogg files, but can also used for other purposes.
The ht://Dig system is a complete WWW indexing and searching system for a domain or intranet. This system is not meant to replace the need for internet-wide search systems like Lycos, Infoseek, Google, and AltaVista. Instead, it is meant to cover the search needs for a single company, campus, or even a particular sub-section of a Web site.
Local Domain Search Engine is a distributed search engine. Nodes index local documents, and multiple nodes can be clustered to bigger nodes. There is a plugin mechanism to support new file formats (currently text, HTML, PDF, Zip, and GZip are supported). Files can be gathered via HTTP and from file systems, but this is extensible. Retrieval is done with a fault tolerant algorithm, so misspelled words can be found. Querying is possible with an applet, an application, a servlet, or via an XML interface.