Is NVASTC open source and still under maintance?

The NVASTC introduced in https://developer.nvidia.com/content/astc-compression-gets-cuda-boost has greately increased my workflow efficiency on compressing textures. However I can hardly find any further information about this marvelous tool except for the article above, while the article was published 3 years ago. So I am wondering if it is still under maintaince, and if there is any possibility that NVIDIA publish its source code?