A video processing framework with simplicity and backward compatibility in mind
VapourSynth-Classic is a fork of VapourSynth R55 to provide long-term stable API: If your vpy script works under VapourSynth R54, then it should continue to work for the foreseeable future.
We simply do not break vpy-level API.
Looking for the documentation? Read the documentation here: VapourSynth-Classic Documentation
For build instructions, visit Windows Compilation and Linux and OS X Compilation