This project is the .NET version of POI Java project at http://poi.apache.org/. POI is an open source project which can help you read/write xls, doc, ppt files. It has a wide application.

For example, you can use it to

a. generate a Excel report without Microsoft Office suite installed on your server and more efficient than call Microsoft Excel ActiveX at background;

b. extract text from Office documents to help you implement full-text indexing feature (most of time this feature is used to create search engines).
c. extract images from Office documents

d. generate Excel sheets that contains formulas

To get the latest code, please visit https://github.com/tonyqus/npoi.