Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
Update: I had to install the previous eclipse version (2019-12) to get things working again. Is there a known incompatibility regarding 2020-03 that I missed?