This package is meant to be installed automatically by the Anniversary Edition: http://mods.oni2.net/node/276. If you are reading this description directly while browsing the Depot and want to install the Daodan DLL without installing the AE, place the files from the ZIP's win_only\ directory into your Oni\ game directory alongside Oni.exe. Then, replace your Oni.exe with the one found here: http://mods.oni2.net/node/231. You should also place realbink.dll in the same directory, which restores the Bink playback required for Oni's intro and outro movies.

The Daodan DLL patches Oni.exe to be able to run on modern machines, as well as adding new features. The Daodan DLL is a file called "binkw32.dll", but note that this is totally different from the binkw32.dll that comes with Oni. See this page for more information: http://wiki.oni2.net/Daodan_DLL.