Vial is an open-source cross-platform (Windows, Linux and Mac) GUI and a QMK fork for configuring your keyboard in real time.
Vial is a completely open project, with sources for all components publicly available on GitHub.
Vial is decentralized: with Vial you do not have to submit your keyboard as a pull-request to any third-party repositories before it can be used in the GUI; instead, the keymap JSON definition is stored within the keyboard firmware and is retrieved at runtime.
For information about using Vial and porting a new keyboard to Vial, read through the manual entries linked in the sidebar on the left.
Have a feature suggestion for Vial? Feel free to submit it at the dedicated feedback website.