VLC media player is a free, multi-purpose media player. Its price and ability to support a wide variety of media formats makes it a popular choice for enjoying movies, video clips and audio on a personal computer. Although the player has a number of features that make it a good choice for personal entertainment, the developers concentrate on enhancing the software. Not the documentation. Many features, including the ability to split video output across several screens, are not documented on the official VideoLAN website. In the case of VLC, lack of documentation doesn't mean lack of ability.
Open the VLC player. Click "Tools" in the player's main menu.
Click "Preferences" in the drop-down menu.
Click the button next to "All" in the "Show Settings" box at the bottom left side of the Preferences window.
Click the arrow next to the "Video" entry. Click the arrow next to "Filters" under the Video entry.
Click the "Image wall" entry. Enter the number of vertical splits desired in the "Number of columns" box. Enter the number of horizontal splits in the "Number of rows" box.
Click the "Save" button.
Exit and restart the VLC player. Subsequent videos are split into multiple windows that can be moved to additional screens and resized as needed.
Older versions of VLC have "+" signs next to the Video and Filter entries. Click on these to expand the available options. In this instance, the version change is only cosmetic.