In the wiki I thing it would be better to have the title at the top of the article in big characters (Other than the "handmade.network » wiki » Page title" ).

Is the revision history icon suppose to be a rectangle containing 25 05 ?

In articles I thing the difference between level one headings and level two headings is no visible enough. For example in the Virtual Memory article I don't clearly see that TLB is level one after reading the level two paragraphs.

After watching the education stream I can confirm that the revision history icon is not working for me. I'm on Windows 7 64bit, Firefox 57.0.4 64bit. I also tested it in Internet Explorer 11 and it doesn't work either.