ClosedXML makes it easier for developers to create Excel 2007/2010 files. It provides a nice object oriented way to manipulate the files (similar to VBA) without dealing with the hassles of XML Documents. It can be used by any .NET language like C# and Visual Basic (VB). ClosedXML allows you to create Excel 2007/2010 files without the Excel application. The typical example is creating Excel reports on a web server.