Excel-DNA

Excel-DNA is a project that aims to integrate .NET to Excel so that users can manipulate spreadsheets better and create macros. The idea behind the library comes as a consequence of that Visual Studio Tools for Office (VSTO) was rather complicated to use and often lead to deployment complications and add-in limitations.
The integration entails that the spreadsheet accepts VBA code and hence, further functions and macros can be integrated for smoother operations. Nevertheless, the tool can come in handy for other developers who perhaps want to create various Excel add-ins. 
The library works with various Excel editions, from 97 to 2016. In the eventuality that it is used with Excel 2007 and later versions, then advanced features such as multi-threaded recalculation, registration-free RTD servers and customized Ribbon interfaces are supported. 
Additional advanced features worth mentioning include Custom Task Panes and offloading UDF computations to a Windows HPC cluster. According to the developer, the latter can be exposed to Excel directly without any modifications. 
Integrating the library is done via an .XLL file that has the role of exposing the .NET code to Excel. The accepted code can be either DNA text-based files written in C# and Visual Basic or directly compile DLL .NET libraries.

System requirements