Using machine learning to find the lowercasest and uppercasest letters.

If you're playing Stardew Valley (there's a been a bit of a resurgence with the recent updates), then I recommend using Stardew Profits. I love these little single-serving webapps that do exactly what you need and are served from

This is one of the most perfectly evil things I've seen in a while - edible fake silica gel pouches

Sudoku solving Jan 29th

I don't know how I stumbled into this Sudoku video, but it's extremely relaxing.

13,000 regular expressions seems like a great solution to this particular problem - how the Guardian built an automated style guide checker

Adventures in code: PHP unit testing Jan 22nd

If you want to make a PHP package available that works on versions of PHP from 5.3 to 8.0, testing is a giant pain. There are versions of phpunit that work for each, but none that works for all. Additionally, the basic class names changed at some point in the past. Getting all of this to run on Travis, including running code coverage (but only once for each build!) was a complex series of trials, but I finally figured out the correct .travis.yml incantation, along with a magic test wrapper for aliasing classes

A blast from the past - Achievement Unlocked is a fun parody of achievements in modern games. The link for hints is broken, but the solutions can still be found here

I've updated my 2020 reading list. In contrast to 2019, where I finished 116 books, I only completed 72 in 2020. This is largely due to the pandemic, no longer having a daily commute, but also not traveling around the world.

My favorites of the year:

  • Agency - Drones, Book 3, by William Gibson - Excellent finale to his latest trilogy and set in San Francisco.
    • Edit: Simon Wistow points out that it's really book 2, and that Archangel is 'book 1.5'. A third book might still happen
  • Billion Dollar Whale, by Bradley Hope - Incredible story of the man who stole billions of dollars from the Malaysian government and has evaded justice

I created a couple of google maps helpers when I was working on personal projects a few years ago, but this tutorial on adding custom tooltips to overlay shapes was super useful.

I can't remember who linked me to blocks, but it's pretty fun. The sound effects are... something else. Unfortunately it seems to sometimes lose your progress.

Subscribe via RSS | Older posts »


This is the personal website of Cal Henderson, Slack co-founder & CTO.

I give occasional talks, write code and sometimes articles.

» About Cal


» Twitter
» GitHub (more, moar)
» Flickr Photos
» Flengbot (Group Linklog)
» Shakefeed (Best of Mlkshk)
» Building Scalable Wesites (My book)
» My Conference Talks


» Glitch: Bees!
» Starcraft: Bees #187
» Diablo 3: Bees #1517
» Steam: iamcal
» XBox Live: iamcal
» EVE: Demitra
» Weewar: iamcal
» Kingdom of Loathing: bees (id #29410)
» My WoW theory blog

flickr twitter facebook linkedin vimeo WoW kickstarter github stack overflow glitch