Ayende @ Rahien

My name is Oren Eini
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The CLR Sources

time to read 1 min | 85 words

I have no idea why this isn't in much wider circulation, but this is huge.

ScottGu has announced that Microsoft is Releasing the Source Code for the .NET Framework Libraries.

I am disappointed to see that even in the tiny source code samples that he has in the post I have violent disagreements (they speak about sealing stuff, which I have serious objection to).

This hopefully means a lot less ReflectorDebugging, although I am not sure about all the implication that this has.


Ted Neward

Oren, it's NOT the CLR sources (meaning the source to the CLR itself), but the Framework Class Library sources that are being MS-RL'ed, and even at that only a subset are being made available. (I've posted a complete Q&A document Microsoft sent me over on my blog.)

Still, for those who are interested in the CLR sources, remember Rotor. :-)


Mmm... you can compile a special version of System.Web assembly with an additional constructor for HttpContext where you can inject a mock for HttpContext.Current property.

Doesn't it sound lovely ? :-)

TypeMock, be afraid... very afraid


I am not sure there are many implications beyond a lot less reflector debugging, since the license is for reference and not for someone to make and distribute custom versions of the .net Framwork thankfully.

Colin Ramsay

Dan: the license restricts you to debugging and not recompiling...


I think its great news, but the implications are yet to be seen. Even more curious is the motivation for this.

pete w

I wonder if people will start to tailor their code more around the internals of a given CLR version and less around the exposed interfaces... the result? Higher dependency on a specific version of the runtime.

Eric Anderson

It seems like not everyone sees this as a good thing. While I am certainly not a conspiracy theorist, this would appear to be a good way for MS to get their claws into existing about source projects. To read more about that, check out what Steven Vaughn-Nichols has to say about it here:



So basically you can now see the code that is causing the bugs in the framework but you still can't do anything about it. They're clearly taunting me. . .

Ayende Rahien


They already do.

I have a calendar control that does REALLY nasty things to System.Web.UI.Calendar.

Nasty as in this.GetType().GetField("_cantRecall").SetValue(5, this);

Gian Maria

It could be interesting seeing some of the internals of the FCL :P, but actually is only a matter of not using reflector, I hope that the code will have some comment to make it clearer.


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