Oxygen Icons Set in PNG format only updated from http://www.archlinux.org/packages/extra/any/oxygen-icons/download. This repository can be used by people that want to provide oxygen icons theme to non opened system like Windows and Mac OS X easily.
Following the archlinux.org link in the README page downloads a tar.xz of the pkg file. After unpacking the download with Archive Utility on OS X, I attempt to open the install the pkg and it delivers a message that “oxygen-icons-15.04.3-1-any.pkg” is damaged and can’t be opened. You should move it to the Trash.
Opening with the Unarchiver software works, however.
Can you please clarify what is the license for this particular Iconset?
The one downloadable form Archlinux is LGPL; however, based on the README file that accompanies these icons, it hints they may have a more permissive license.
Unfortunately, there are a lot of missing files in both the repository and the compressed file. The missing files are represented as symlinks to themselves, with zero size.