The default binaries in the AjaxControlToolkit (version 40412) include language folders that can be a bit cumbersome if you don't need the multi-language functionality...

Even when you delete them, they will come back.  It seems the only way to get around this is to download the source code and build the DLL without the language references.

To fix this, I downloaded the source code from CodePlex.  When you open it in Visual Studio 2010 you will get a solution that looks like this.  The project to look at is in "/Server/AjaxControlToolkit/"...

Note: I got some errors trying to load the solution, and found out that I needed to also install the Ajax Minifier

We need to edit the .csproj file.  To do this, right-click the project and choose "unload".  Then, right-click it again and choose "edit".  This will open the .csproj file in Visual Studio.  Look around line 662 and you will see some "EmbeddedResource" tags that look like this...

      ScriptResources\BaseScriptsResources.ar.resx
      Designer

Remove/comment all of those except for the one the tag that has the file named "BaseScriptsResources.resx" (this is the default resx, and we need this for English).

After doing this, right-click the project again and choose "Load".  Then build the Solution.  Your new DLL will be located in "/AjaxControlToolkit.Source/Server/AjaxControlToolkit/bin/Release/", and there should be no more language files.