Backup Github for the Oleg Bliznuk original: https://bitbucket.org/OlegBliznuk/openvdb_to_softimage/src/master/
In order to build you have to install Visual studio (2010-2015) on Windows or GCC if you are on linux. Next, install qtcreator IDE (make sure it is compatible with your vs/gcc version). Define XSISDK_ROOT system variable, so it will point to the actual softimage sdk folder, for example: /usr/Softimage/Softimage_2013_SP1/XSISDK or C:\Program Files\Autodesk\Softimage 2013 SP1\XSISDK
Clone the repo and open openvdb_to_softimage.pro in qtcreator, configure your toolchain and build. To connect the plugin in softimage, open the plug-in manager and connect "repofolder/build/XSI_OPENVDB_Workgroup" as workgroup. Restart Softimage.
Check out the binaries in the downloads section ( and do not forget to install vs2015 redistr on windows )