The first beta of the v4.0 .NET Framework is now available, and with it comes a lot of changes to the CLR's security system.  We've updated both the policy and enforcement portions of the runtime in a lot of ways that I'm pretty excited to finally see available.  Since there are a lot of security changes, I'll spend the next month or so taking a deeper look at each of them.  At a high level, the major areas that are seeing updates with the v4 CLR are: 

Like I did when we shipped the v2.0 CLR, I'll come back and update this post with links to the details about each of the features we added as I write more detailed blog posts about each of them.

Tomorrow, I'll start by looking at probably the most visible change of the group - the update to the CLR's security policy system.