StreamCruncher is an event processor. It supports a language based on SQL that allows you to define "event processing" constructs like sliding windows, time-based windows, partitions, and aggregates. Such constructs allow for the specification of boundaries (some are time sensitive) on a stream of events that SQL does not provide. Queries can be written using this language, which in turn can be used to monitor streams of incoming events. It also provides a feature similar to materialized views. Joins and sub-queries are also supported to allow event co-relation. A database is used underneath to do the heavy lifting. Pattern matching or multi-stream correlation are also possible.
Objectkitchen is small object-oriented database written in Java. It is currently only usable from PHP, but libraries for other languages (Ruby and Java) are currently being written. You use objectkitchen to store your data in objects, with relations to other objects handled simply by setting the value of an instance variable to another object. Objectkitchen is currently tuned to handle many requests to small datasets, such as those found in most Web sites.
ZAP! is a module which makes it fairly straightforward to build WWW-based user interfaces for groups of Z39.50-based information resources. It hides much of the complexity of the underlying protocol and requires mostly an understanding of HTML and some understanding of the Z39.50 database model.
With the PHP Text File Interface (Txt-Db-API) you can access normal text files like an SQL Database. You don't need any special database software on the Web server, yet you can still use SQL calls. You can use the API to create, query, change, or delete SQL tables, and you don't have to bother with the text files themselves; almost everthing can be done with the supported API calls. The Txt-Db-API is object-oriented and very simple to use.
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.
Maccess helps to analyse data in databases; it is a Web interface to an SQL server. Its main features are user friendly query creation for SQL server; selective, grouped, and crosstab queries; various outputs (XML, HTML, TXT, graphs, and Europe map); data ungrouping in grouped queries; creation of Web links and definition of CSS styles for all values in output; ability to format numbers, dates, and times; and input and data update.
Tdbengine is an RDBMS with an integrated programming language. It represents the enhancement of the famous DOS-TDB, and is designed to handle databases on the Web. It connects to the Web server using the standard CGI interface, or runs on the command line. It is very small (about 400 KBytes), extremely quick, and easy to administrate. Its features are full text indexing, an automatic data link system, and the script language EASY, which replaces the commonly used SQL with its modular code.