mrViewer, the professional and open source tool for hdri viewing, flipbook and video and audio playback is now at v5.5.2. This update adds better MacOSX support (Catalina and Mojave), adds syncing of the timeline when multiple clips are loaded, etc.
For a list of features, please refer to the mrViewer web site at:
https://mrviewer.sourceforge.io
For downloading the binaries, go to:
https://sourceforge.net/projects/mrviewer/files/