In a Microsoft TechDays seminar, i heard a speker saying that Microsoft’s .Net Library can be modified to optimize for your specific purpose and performance (He didn’t said it exactly above, but ment to say it).
I wanted to know that is it Possible to do so, wouldn’t then .Net become a kind of open source library
The .NET Micro Framework was open-sourced not long ago. As were IronPython and IronRuby.
Beyond that it gets difficult. SSCLI20 was released 5 years ago but not as open source. Its Shared Source license allows it to be used to implement your own CLR, the Mono project took advantage of that. Selected portions of the framework source code are released under the Reference Source license. You can look at it to assist in debugging but you can’t modify it.