Assemblies of next version of .NET Framework are divided in two groups - "green bits" and "red bits" as they are called inside Microsoft.
The red bits include all the libraries that shipped before as part of the .NET Framework 2.0 and 3.0 (such as mscorlib.dll and system.dll). To maintain a high assurance of backward compatibility for Visual Studio "Orcas," changes in the red bits have been greatly limited.
The green bits assemblies are the brand new libraries with additional classes that work on top of the red bits assemblies. Most of the classes listed in this column are in the green bits assemblies (such as system.core.dll), with a few involving limited changes in the red bits assemblies.
The CLR's contributions to the new libraries include:
- A new add-in hosting model, which was discussed in the last two editions of CLR Inside Out
- Support for the Suite B set of cryptographic algorithms, as specified by the National Security Agency (NSA)
- Support for big integers
- A high-performance set collection
- Support for anonymous and named pipes
- Improved time zone support
- Lightweight reader/writer lock classes
- Better integration with Event Tracing for Windows® (ETW), including ETW provider and ETW trace listener APIs
There are also new crypto classes that covers Suite B set of cryptographic algorithms.
for more info read New Library Classes in "Orcas"