pcb-rnd is a rapid moving independent project started in 2013, but roots tracing back to the early 90s, to PCB.
From the pcb.html documentation:
Pcbwas first written by Thomas Nau for an Atari ST in 1990 and ported to
X11in 1994. It was not intended as a professional layout system, but as a tool which supports people who do some home-developing of hardware.
In Fall 2013, Tibor 'Igor2' Palinkas started an unofficial fork of PCB to make and share random changes and improvements (hence the name "-rnd"). Over the following years the fork was officially announced, adopted additional users, and reached various milestones, including modularization of the code base, a better configuration system.
In 2015, the project switched pace: lot of hours invested and many new developers and contributors joined, pcb-rnd started to grow rapidly. Most of the code base has been extended, cleaned up or rewritten.
In 2016 and 2017 pcb-rnd went on growig in number of developers, contributors and users. The number of long standing bugs and misfeatures fixed and missing features implemented grew a lot too. This affected major components as the plugin system, the I/O (file format support) subsystem and even the data model pcb-rnd operates on.
At the moment, pcb-rnd is not part of any EDA suite.
A more complete history can be found in the pcb-history project.