Online AB Loop Player for YouTube videos and local media files
media9 LaTeX package for embedding multimedia and 3D content into PDF documents
ocgx2 LaTeX package for creating PDF Layers (OCG)
xsavebox LaTeX saveboxes for repeating content without code replication, based on PDF Form XObjects
pst-ode PSTricks package (LaTeX, Plain-TeX) for solving initial value problems for sets of Ordinary Differential Equations (ODE) using the Runge-Kutta-Fehlberg (RKF45) method
animate LaTeX package for creating PDF animations and animated SVG from graphics files and inline graphics.
Chromium-based browsers (Chrome, Opera) are recommended for playback of animated SVG because of their extremely good rendering performance.