libdbi implements a database-independent abstraction layer in C, similar to the DBI/DBD layer in Perl. Writing one generic set of code, programmers can leverage the power of multiple databases and multiple simultaneous database connections by using this framework. The plugin architecture allows for new database drivers to be easily added by a third party with flexible licensing.
SQLScreens is a simple relational database screen form generator written in TCL/TK. It will let you create query screens very quickly by specifying what data (tables and columns) you want to see and what operations should be allowed (query/update, etc.). It will take care of creating the user interface and the behind-the-scenes SQL. SQLScreens can be used with different backend database systems, and includes direct support for MySQL, SQLite, and INFORMIX, and ODBC for others.
Bugzilla is the leading open-source/free software bug tracking system, with high-profile installations at mozilla.org, GNOME, Red Hat, and NASA, among others. It features a comprehensive set of fields, attachment management, inter-bug dependencies, email notification of changes, a powerful query interface, reporting, and Web, XML, email, and console interfaces. It can be managed entirely using a Web-based UI. The user UI is customizable using templates.
Aubit 4GL compiler is a programming language based on (and compatible with) Informix-4GL. It provides an easy way to generate screen/form based programs, since statements for handling Windows, Forms, Menus, SQL, and similar are built-in. With support for SQL statements forming an intrinsic part of the language, it's especially suitable for developing database-oriented applications. Database connectivity is provided for PostgreSQL, MySQL, Informix, and others via ODBC. It supports both ncurses (console mode) and GTK+ (GUI mode) output.
PM Report is a PHP/MySQL report generator. It creates customizable reports and is very simple to setup and use. You can select which database, table, and individual fields to use on your report. You can also select the order in which the fields should appear on the report, the field you would like to group by, the field you would like to sort by, and whether or not you would like a total for each column. Once the report has been generated, you can highlight individual rows and export the results to CSV.
DBKiss is a one-PHP-file database browser that is easy to upload and use. It supports MySQL and PostgreSQL and features import/export of data, searching of the whole database or single tables, an advanced SQL editor, saving of templates, multi-query execution with pagination, and more.