New features

Official Spout and Syphon support for both video input and output :-)
Ability to connect / disconnect multiple devices at once (thanks @RobinMontferme !)
Ability to copy-paste parts of the curve in automation curves #1074 #1364
Spline: double-click on a point now removes it
(work-in-progress) copy-paste of nodes
(experimental) Live preview widget in the inspector for video processes
(experimental) Direct PipeWire audio back-end on Linux. For now score needs to be built from source.
When quitting the splash screen with "Esc", an empty document will be created as the previous behaviour was confusing.

Changes

Do not autotrigger things anymore if they do not have any visual trigger enabled. For instance this could happen if copy-pasting the first elements of the score and hitting play, as the first state was considered a root of the score (and this state is being copied). This has proven to be confusing. To keep non-root parts of the score auto-playing on start, simply add a trigger with a "True" condition.
(experimental) a big part of the audio driver interaction has been rewritten to make things more asynchronous. The dreaded "Audio engine stuck" pop-up should be a thing of the past, but there is the possibility of corner case bugs which may have crept in.

Fix scaling of the splash screen with non-integer zoom levels (e.g. 150% zoom). #1241
Do not submit undo/redo command if clicking on a node without moving it.
Allow to deselect things in nodal view by clicking in the background.
Fix issues with broken cable connections when editing at runtime
Fix that shmdata outputs did not send the framerate info to GStreamer
Improvements on the inspector UI
Add a failsafe that will stop score from trying to start with opengl if it crashed during startup.
If the file "failsafe.bit" exists in the score configuration folder, e.g. ~/.config/ossia, then score won't try to start rendering its UI with the GL paint engine.
Many improvements on the library performance.
Add a timer to update the timebar regularly when GL does not drive the UI (#1357) and fix some other UI bugs when not using OpenGL
Fix that play-from-here past the end trigger of the root interval did not work
Allow infinite dezoom. Fixes #444
Fix that the focus on the score window would be lost on macOS after adding an OSCQuery device, requiring an alt-tab to get focus back.
MIDI: Do not send undo commands when clicking on a note without moving
Improvements to auto-scroll
Improvements to the video inspector
Fix some remaining live-code issues with the JS process