GNOME-DB is composed of several components, not all of them being mandatory. So, depending on what you intend to use it for, you might need just libgda (for developing database applications with no GUI), libgnomedb, if you intend to write data-oriented widgets, and mergeant, for database administrators and application developers.
In addition to that, you might want to use the unstable or the stable versions. For people helping in the development, unstable is what you need. If in doubt, download the stable version.
libgda and libgnomedb have been developped primarily on a Linux OS, but they should compile and run on any Unix system where all their dependencies have been installed. As of versions 3.2.x Microsoft Windows will also be supported, please see the GnomeDB on Windows page for more information about that platform (including compiling instructions).
Binary packages
Linux / Unix
This page does not contain any binary distribution of Gnome-DB. Refer to the packages offered by the Linux distribution to install Gnome-DB (I can add links to externally made binary packages, though).
However some Linux distributions contain already installable packages, which can easily be installed.
Windows
Not yet.
Sources
Stable version
The current stable version of libgda/libgnomedb is 3.0.0, available at:
Unstable beta version
Unstable versions do not always work as expected, so make sure you don't use them in production environments with sensible data. However the current unstable version is in beta state which means very few API changes, and bug fixes.
The last unstable version is 3.1.2, available at:
Also the very latest sources are available from the GNOME SVN server, where all source code is stored and which is used by developers to work on new features and bug fixes.
To download the SVN version of the libgda (the V4 branch is the active development branch), libgnomedb and mergeant modules you should run:
svn checkout http://svn.gnome.org/svn/libgda/branches/V4-branch libgda
svn checkout http://svn.gnome.org/svn/libgnomedb/trunk libgnomedb
svn checkout http://svn.gnome.org/svn/mergeant/trunk mergeant
More information about the GNOME SVN server can be found at http://live.gnome.org/SubversionFAQ.
There is no current released unstable version of Libgda/Libgnomedb.
Mergeant
There is no stable version of Mergeant yet, however an unstable version exists: