NATRON - Free and Opensource Digital Compositing Software
Free and Opensource NUKE alternative.
Natron is a free and open-source node-based compositing software. It has been influenced by digital compositing software such as Nuke, from which its user interface and many of its concepts are derived.
Natron supports plugins following the OpenFX 1.4 API. Most open-source and commercial OpenFX plug-ins are supported.