Qt SQL Browser

A graphical front end for any ODBC compliant database [GPL]
http://www.mobiustech.net/qtsql/

Open Source Database Summit

September 23-25, 2001 in Providence, Rhode Island, for developers and IT professionals.
http://www.osdn.com/conferences/osdb2/

Clip

Object oriented, CA-Clipper and Xbase compatible compiler.
http://www.english.itk.ru/clipper/index.html

Seva Software - ArunaDB

Database server written in Ruby that supports tables, indexes, triggers, sequences, views, stored procedures, and transactions.
http://www.arunadb.com/

Fast DB

Main memory object-relational DBMS featuring log-less transaction recovery, tight C++ integration, query language like SQL. Optimized for all data being held in RAM.
http://www.geocities.com/SiliconValley/Orchard/5802/fastdb.html

The TDB Replication System

An open source suite of software that provides a high-performance, replicated, distributed peer-to-peer Unix DBM style database built on TDB.
http://tdbrepl.inodes.org

Index of Publicly Available Database Software

Comprehensive list of research and other free database systems. Also includes some benchmarks. Maintained by ACM SIGMOD.
http://www.acm.org/sigmod/databaseSoftware/

SourceForge.net Database Foundry

Project descriptions, news, guides, forums, and articles.
http://foundries.sourceforge.net/databases/

SQLite

A complete SQL database engine in a C library. [Open Source, Public Domain]
http://www.hwaci.com/sw/sqlite/

Ocelot Computer Services Inc.

The Ocelot SQL DBMS adheres closely to the ANSI/ISO SQL standard. The site has software downloads, tutorial information, and reviews of SQL or general DBMS books. [Mozilla and GPL]
http://www.ocelot.ca

ASP.NET Enterprise Manager

Download a web-based, open-source version of Microsoft's Enterprise Manager for SQL Server that can be used to administrate SQL Server and MSDE with a web browser.
http://www.aspenterprisemanager.com/

Anubisnet

Develops open source database (dBASE for Linux and Windows) applications and software for Multimedia (MPaxx, CMMS).
http://www.anubisnet.de

picoSQL

picoSQL is a SQL-based, multi-user, client/server RDBMS, derived from a commercial project [GPL].
http://www.picosoft.it/picosql/

Backplane, Inc.

Available to both open source and corporate developers, Backplane is a replicated, transactional, fault-tolerant relational database core. Currently supported on Linux and FreeBSD.
http://www.backplane.com

iSQL-VIewer

An SQL browser tool that works with any JDBC 2.0 or higher driver. [Open Source, MPL]
http://isql.sourceforge.net/

OSDB: The Open Source Database Network

News, information, and tools related to open source database platforms.
http://osdb.org

RekallRevealed

Rekall is an open source database front end, in the style of Microsoft Access. It is built on Qt and KDE and runs on Linux and Windows. Open source drivers available for MySQL, PgSQL and XBase (DB4 via a wrapper library) [GPL]
http://www.rekallrevealed.org

SiteSure Software

Provider of database server software and online catalog programs.[Commercial]
http://www.sitesuresoft.com

Persistent Data Objects

A flexible, lightweight object oriented database system in C++ with an extensible back-end store design. MFC compatible version available. [GPL]
http://www.geocities.com/brianleeprice/pdo.html

L.A.B. Project - Linux Advanced Business Tools

Provides small and medium sized businesses with advanced tools that can be used to build business applications.
http://www.lab-project.net/

SimpleSQL

Download an easy to use database featuring Java and C++ compliance, a transactional server, a server-free SQL component, and a 64-bit portable database file. Site also offers tutorials and installation instructions.
http://www.simplesql.org

ITTIA

Provides small footprint, high performance, and easy-to-use embedded database solutions. Also sells technical support and consulting.
http://www.ittia.com/

Mneson

Pure Ada database including library and tools for persistent graphs of basic values (integer, string, float).
http://www.liacc.up.pt/~maa/mneson

tdbengine - The turbo database engine

tdbengine is a small but powerful RDBMS written in PASCAL. It runs on Linux as well as on Windows machines.
http://www.tdbengine.org

ChurchInfo Church Database Application

ChurchInfo is a php/mySQL database to keep track of people, families, groups, pledges and payments, sunday school classes, etc.
http://www.churchdb.org

One$DB: Open Source Database

Free and open source version of Java database Daffodil DB. Available in both network and embedded editions.
http://www.daffodildb.com/one-dollar-db.html

Web based reporting and query tool

ART is a lightweight JAV / J2EE, multiplatform web based query tool and reporting environment. Supports tabular, crosstab, charts, scheduling; data exportable to spreadsheet.
http://art.sourceforge.net

SQLite

C library that implements a self-contained, embeddable, zero-configuration SQL database engine. Linux, Windows.
http://www.sqlite.org/