The new compression enhancements in .NET 4.5 provide updated handling of the deflated streams and the GZIP compression handling. Additionally the .NET 4.5 Framework provides file compression feature. These are framework specific features.
The main goal of RadCompression is to compress Ajax, service responses and to compress the ViewState. This is the main goal of the RadCompression module. Keeping this in mind there is no reason for RadCompression to not work with the latest .NET Framework unless there is a breaking change. Since now, we have not heard of such breaking change from Microsoft.
If you want to compress files you should use the new compression feature of .NET Framework 4.5 instead of RadCompression.
the Telerik team
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