Reddit reviews Quake Level Design Handbook

You mean QED (aka qED / Quot Erat Demonstrandum) the shareware editor written by Matt Tagliaferri (who also wrote the Quake Level Design Handbook that also came with the editor) or QuakeEd which became QE4 and later QERadiant and from that it evolved a ton of *Radiant derivatives (including GtkRadiant, Doom 3 Radiant, DarkRadiant, COD4 Radiant and lately Black Radiant and idStudio)?

I ask because i find it surprising that someone actually knows about qED, it seems to be like a tiny footnote among the tons of editors that were written for Quake (and still being written, like the new Trenchbroom editor). AFAIK it was considered a simple editor for a little while but was quickly surpassed by Worldcraft (which was bought by Valve, bundled with HL1 and eventually renamed to Hammer).