Natron
32 bits floating point linear color processing pipeline : all frames are represented as floating-point RGBA samples with premultiplied alpha, permitting the use of alpha compositing operators defined by Thomas Porter and Tom Duff.
Support for multi-core architectures: all processing is multithreaded using a thread pool pattern.
Color management is handled by the OpenColorIO library, including support for the ACES color encoding system proposed by the Academy of Motion Picture Arts and Sciences.