In about 2013, I migrated the Glasgow Haskell Compiler from "read .patch files on bug reporter" that I joked about, to using Phabricator. For a couple reasons, but at the time one of them was not stacked diffs. It was because GitHub was so bad for review it didn't even have side-by-side diffs! It was a total non-starter for me for those reasons among others.
But that actually wasn't the first time I migrated a team to a code review tool. My first job in 2009 was a very small tight knit team of engineers in a single room in Houston, and I remember thinking it would be really good to get reviews of my code from other people, and to read the things they wrote so I could better understand the codebase. So, the first thing I did in the first few months was pester my manager to set up... ReviewBoard! And we all really liked it.
So I guess this is a way of saying thanks for RB! I still think of it fondly from time to time. And because of it, Code Review has always just been a huge part of my career, almost since day one (and I could still do more of it.)