The usual definition of open source is the Open Source Definition,[1] which was adapted from the Debian Free Software Guidelines[2]. The sixth item prohibits discrimination against fields of endeavor, which this new license would violate.

It's more like an especially generous version of shared source than open source.

[1] https://opensource.org/osd [2] https://www.debian.org/social_contract#guidelines

I do not agree that some organization can define what open source is and everyone else can't. That's not free.

It’s worth noting (and Redis Labs has attempted to note in the body of the article) that Redis (the database) remains open source, as it always has been. Neither the “Common Clause” change or this change affect the database, just the modules published to extend Redis, by Redis Labs.

They are the same. The full .NET framework effectively had the full source code available to read as the "Reference Source" but there was never any doubt it was proprietary.

https://referencesource.microsoft.com/

You can mince words and make inconsequential adjustments to proprietary software licenses but they are still proprietary.

The current iteration of the .NET Framework, .NET Core, is proper Open Source under the MIT license. .NET Framework 4.x above is a different beast all-together and requires Mono for cross-platform compatibility. I am guessing you are fully aware of the difference, but worth pointing out for readers who might not be :)

.Net Core is not an iteration of .Net framework.

.Net Core and .Net Framework are separate implementations of .Net Standard.

Though the argument is that because all of the innovation is happening in .NET Core (and indeed the .NET Standard 1.x versions were a game of .NET Core implementing things first and backports eventually made to .NET Framework), the clear indicator seems to be that .NET Core is the present-future platform (ie, the "current iteration") for .NET and .NET Framework the backwards-compatible past. Though Microsoft has walked that messaging back, somewhat, it's very much the case that greenfield projects today are best on .NET Core, and even brownfield projects are welcome on .NET Core (.NET Core 3.0 "Desktop Pack" is now the best way to build and run WinForms and WPF applications).

You can ask Microsoft for access to Windows source code. https://www.microsoft.com/en-us/sharedsource/ Any definition of "open source" that includes Windows is so vague as to be useless.

But that's asking, it's closed until "opened", not "open" per se.

Because there is minimal value in being able to read but not use the source

Not sure the value is minimal. Many people read the .net framework source to get a better understanding even though you weren't allowed to do anything with it