To build the Calculator app, you’ll need a Windows 10 computer and Visual Studio. You might think that this is the same code that’s been shipping for 30 years — it’s a simple calculator ...

To mark the occasion, Gates has released the source code he and Allen wrote for the Altair 8800 – dubbed Altair BASIC – which became the company's first product.

Now you can get the once-coveted Microsoft Basic source code for the 8086/8088 directly from Microsoft in the state you would have found it in 1983.

In the 1970s, Gates and his Microsoft co-founder, Paul Allen, used a computer in Harvard's lab to compose what he calls the 'coolest code I've written.' It's now public for the first time.

Microsoft's embrace and adoption of open source software has continued with the surprising decision to publish the code for Windows Calculator and release it on GitHub under the permissive MIT ...