The db4o core engine used to get built to one big fat .jar/.dll.

From our users on low resource devices we constantly hear requests for a smaller library size. For people using db4o on handhelds and phones like Android, 1 MB seems to be a critical size for an input component. We decided to respond:
We have made the db4o distribution more modular.

For db4o 7.7 we have factored out ClientServer functionality and some optional functionality into two separate Jars/DLLs. The optional package contains primitive Cluster querying, support for working with .NET and Java against the same database, IoAdapters to Debug and for Symbian, a SelfReflector package and all the old tools like Logger, MemoryStats, QueryStats and Statistics.

The names of the new libraries should be fairly self-explaining, but here is a little overview. Assuming you want to work with Java on JDK5, you will need the following Jars, if you rely on the previous functionality of db4o-[version]-java5.jar:
db4o-[version]-core-java5.jar
db4o-[version]-cs-java5.jar
db4o-[version]-optional-java5.jar

Please make sure you don't blindly use all db4o libraries in the /lib/ folder of the download. You would mix db4o versions for different Java versions in that case.

The "java5" in the above names means that the libraries are compiled for Java JDK 5 or higher. You will also find versions for "java1.1" and "java1.2" in the same lib folder. For all Jars that have a "java" in their name, please choose only the one for the platform that you need. All Jars without a "java" in their name are generic and should work for all Java platforms that we support.

On .NET you will have to add the following three DLLs to your project references, to get the same functionality that previously
was completely in Db4objects.Db4o.dll:
Db4objects.Db4o.dll
Db4objects.Db4o.CS.dll
Db4objects.Db4o.Optional.dll

Our embedded users are probably happy with the change. We hope we have not created a big hurdle for all others.

Enjoy!