You can start using db4o within a few minutes following these few steps.
First download db4o on the official download site. There are different releases available on the web site. The latest production version, beta versions, continues build versions and older stable releases. Use the production version at the top to get started.
For each release there's a download for a particular .NET version. Choose the .NET version which you're using. For example .NET 4.0. You also can choose between a ZIP-file or a MSI-installer.
Download the file to your computer. If you've chosen the ZIP-file distribution unpack it. In case you've chosen the MSI-installer run it.
The db4o distribution has following content.
db4o-folder/bin: Contains the db4o database engine and the supporting libraries. This folder contains sub-folders for different .NET platforms like the regular .NET framework, the compact framework etc.
db4o-folder/doc: Contains all the db4o documentation. There's the complete API-documentation (db4o-folder/doc/api/db4o.chm), the tutorial (db4o-folder/doc/tutorial/Db4oTutorial.exe) and the reference documentation (db4o-folder/doc/api/index.html)
db4o-folder/omn: Contains the installer for the Object Manager. See "Object Manager Enterprise"
db4o-folder/src: Contains the full source code of db4o.
Additional online resources are available here: http://developer.db4o.com/Resources
After you've downloaded and unpacked the db4o distribution, you can start using it. The core of db4o is the single Db4objects.Db4o.dll-assembly and has no additional dependencies. The other assemblies provide additional functionality See "Dependency Overview".
To use db4o in your project you only need to add the required assemblies to your project and then you're ready to go.
Here is how to do this with Visual Studio:
That's it, now you're ready to go and can use db4o in your project.