The Anniversary Edition (AE) consists of a mod installer (the "AEI"), the latest patches, and a framework for modding Oni. It makes it easier to install people's mods, create your own, and it keeps Oni up-to-date with patches. See "summary" for links.
Oni's AI originally failed most of the time to properly recognize incoming gunfire and dodge it. The AE includes a patch that corrects this issue, so that the AI can seek cover when being shot at.