This presentation will describe recent changes to the NetBSD code that provides compatability with earlier versions. We will discuss some of the short-comings of the NetBSD-8 implementation, such as the lack of granularity of loadable modules and inability to include all of the compatability code in the loadable modules. We will describe the approaches taken to resolve these issues, and some of the infrastructure changes needed to accomodate them, with detailed focus on the mechanisms which ensure that code being executed does not get unloaded. Finally, we will discuss the current state of the implementation, along with a list of things that remain to be done.