The most current and modern version of AviSynth today is AviSynth+, originally a fork of the official AviSynth 2.xx, but AviSynth+ has since gained widespread recognition and has become the go-to implementation. It rewrote most of the original AviSynth code, and introduced long-sought features such as 64-bit support, multithreading, deep color spaces, support for recent compilers, new scripting constructs (new control-flow constructs such as loops), and increased performance in many areas. At the same time it retained 100% compatibility to the AviSynth 2.5/2.6 series, both for filters and host applications. At the time of writing (2020-12), it is also actively maintained.