In 2016, nine years ago, Andrew announced he'd been working on the new language "Zig" for a couple of months.
In 2018, seven years ago, Andrew announced he'd go full-time on Zig and quit his paying job to live off donations instead.
In 2020, so five years ago, Zig's 501(c)3 the ZSF was announced, to create a formal structure to hire more people in addition to the few already on Zig.
So, "most of its time" is just not true. For "most of its time" Zig was a small, largely independently funded project for multiple people, for a tiny period it was a part-time project, and for a while after that it was solo, but those weren't the majority of its existence.
