When LibreOffice needs to use a custom cursor, which the underlying OS does not provide, it currently uses some really old renderings (which I guess might date back even to 90-ies) for those custom cursors.

Needless to say, these cursors look ugly. It would be great to have them updated. And if "ugly" is not reason enough, how about "all of these cursors are only defined in one size, thus completely disregarding hi-dpi screens (for example, even stock Windows 7 aero_arrow cursor contains two renderings of the cursor: 32x32 and 48x48, both in 32-bit colors).

At the same time, perhaps it would make sense to also drop the ones that are not used anywhere in LibO (I couldn't find any uses of some of the cursors). Additionally, I'm sure there are cases where we are using custom cursors even though the OS provides us with stock ones. I've cleaned that up for Windows in bugs #53148 and #53151, but the situation is likely unchanged for OS X (e.g. #52263, which probably requires special consideration) and Linux.

Current cursor files reside in the following places in the source tree:
Windows: http://cgit.freedesktop.org/libreoffice/core/tree/vcl/win/source/src
OS X: http://cgit.freedesktop.org/libreoffice/core/tree/vcl/osx/res/cursors
Linux: http://cgit.freedesktop.org/libreoffice/core/tree/vcl/inc/unx/x11_cursors and probably http://cgit.freedesktop.org/libreoffice/core/tree/vcl/unx/generic/dtrans

I found it's probably easiest to look for the places defining cursors by Grokking for the word 'airbrush': http://opengrok.libreoffice.org/search?q=airbrush&project=core. Airbrush is one of the cursors that appears to be defined, but never used.

By the way, it might be nice to also generate Unix cursors from PNG files and hotspot definitions during compile time instead of having to define them as two header files. This would make them actually viewable and easier to replace.