See the canonical version of this blog post at the Microsoft Open Source Blog! Ten years ago, Microsoft released the source for MS-DOS 1.25 and 2.0 to the Computer History Museum, and then later republished them for reference purposes. This code holds an important place in history and is a fascinating read of an operating system that was written entirely...

I've been doing not just Unit Testing for my sites but full on Integration Testing and Browser Automation Testing as early as 2007 with Selenium. Lately, however, I've been using the faster and generally more compatible Playwright. It has one API and can test on Windows, Linux, Mac, locally, in a container (headless), in my CI/CD pipeline, on Azure...