I'm confused about the differences and relationships between the various Microsoft ASP.NET AJAX components/libraries/toolkits and particularly the naming of them.

It starts off relatively simple with ASP.NET AJAX itself:

• ASP.NET AJAX 1.0 (available for ASP.NET 2.0 in a separate package called ASP.NET 1.0 Extensions)
• ASP.NET AJAX 3.5 (included with ASP.NET 3.5)
• ASP.NET AJAX 4.0 (included with ASP.NET 4.0)

Then come the various projects on CodePlex and elsewhere:

ASP.NET AJAX Control Toolkit (aka Original Ajax Control Toolkit)

• Samples
• CodePlex
• It seems that the September 2009 Release is the final release of the Original Ajax Control Toolkit and that it's been superseded by...

Ajax Control Toolkit in ASP.NET Ajax Library

• It looks like the old ASP.NET AJAX Control Toolkit has now become part of a larger ASP.NET Ajax Library but is still maintained seperately on CodePlex. This release is in beta at time of writing so presumably if I want to use the "Control Toolkit" I should stick with the September 2009 Release of the Original ASP.NET AJAX Control Toolkit
• CodePlex

Microsoft Ajax Library Preview

• Is this the same as the ASP.NET Ajax Library mentioned above just with a confusing name variation?
• Is the "Control Toolkit" included in Preview 6 and is it older newer or older than the code in Ajax Control Toolkit in ASP.NET Ajax Library?
• CodePlex
• Microsoft ASP.NET Ajax Wiki - note the inconsistent insertion of ASP.NET into the name

Links to useful articles, roadmaps would be useful.