My latest NetRadiant build for Linux, was successfully tested on Ubuntu 18.04, 19.04, Fedora 30, Solus 4 and current Arch and Gentoo:
It's expected users have an already working GTK2 and OpenGL environment, if not installing package libgtkglext1 on Ubuntu, gtkglext-libs on Fedora, gtkglext on Arch and Solus, or x11-libs/gtkglext on Gentoo would be enough. Other libs are bundled.
And my latest NetRadiant builds for Windows:
People with old Intel chip on Windows 10 may face OpenGL issue and unusable white 3D/2D views, those people can workaround the issue by moving everything from mesa3d/ subdirectory right to netradiant.exe to enable software rendering fallback.
I'm investigating macOS builds but they are not ready yet due to some GtkGLExt issue on that system. The Windows build is known to work well on macOS using Wine, so that can be used as a working fallback by macOS users.
It's built from NetRadiant upstream repository at Xonotic:
Please report issues there.
Unvanquished game pack and daemonmap tool (to build navigation meshes) are included.