I just tested that Okular can show these notes of a PDF file that was annotated using Mac Preview. The Okular version I tested was 0.16.5 (very old version, you will very likely have a newer version than that). Okular uses KDE libs but doesn’t require installing the full KDE desktop. Most Linux distros should have it. For instance. On Ubuntu/Debian. sudo apt-get install okular On Fedora/CentOS. sudo yum install okular
Annotate: Signature.