One thing that I always did when learning a new language was to implement a GUI blogging client. Blogging has always been one of the most fun parts of the internet for me and Dave has played a pivotal role in shaping this. Heck, I blame him for my love of outliners.
Still, it was bittersweet when he blocked me on Twitter after a disagreement opinion on the fundamental role of journalism in a democratic society. I wish there was a better exchange at the time, he posted an open public question about the role of journalism, I've answered truthfully as someone who is married to and walks with journalists. And poof, block.
That sucked but I still hold a lot of the things he created quite dear. I'm right now implementing blogging libraries for Racket and maybe even a new GUI client soon, and for that fun, I thanks that guy and his 25 years of blogging stuff.