Some content of the Developer Zone has been restored. Right now you can find Documentation about C++, Java and .Net API for Open Inventor 9.9, 10.2 and the upcoming 10.3. You can also find Download Pages for these three versions.
We are doing our best to add all the missing content. Some issue may appear during the process as we are trying a lot of things to be sure all you need is available as soon as possible.
We sincerely apologize for any inconvenience.
Open Inventor Team.