What is downkyicore?

This is a cross-platform desktop app for downloading videos from Bilibili, a Chinese video-sharing platform similar to YouTube. The app is written in C# using a UI framework called AvaloniaUI, which allows it to run on Windows, Linux, and macOS. It was built by a developer who used an existing Windows-only Bilibili downloader called DownKyi and found it excellent but unusable on macOS, so they rebuilt it with cross-platform support. The downloader supports high-quality video formats including 8K, HDR, and Dolby Vision. It can handle batch downloads, meaning you can queue multiple videos at once rather than downloading them one by one. There is also a built-in toolbox with utilities for extracting audio or video from a file and for removing watermarks. The app bundles its own copies of .NET 6, ffmpeg, and aria2, which are the underlying tools it uses for playback processing and downloading, so you do not need to install those separately. Downloaded files land in a default location that varies by operating system: a Media folder inside the app directory on Windows, the Application Support folder on macOS, and the .config folder on Linux. The README includes a disclaimer noting that the software is intended only for personal learning and exchange, that the copyright for any downloaded content belongs to its original creators, and that users should delete downloaded files within 24 hours. The author states they bear no responsibility for copyright issues arising from use of the tool.