ClosedXML makes it easier for developers to create Excel 2007+ files.

The Microsoft CRM Documentation Generator is an add-in for Microsoft Office Excel 2007 to automatically generate documentation for Microsoft Dynamics CRM 3.0

DataFromFile is a small class (written in C#) which makes it easy to deal with data files such as Excel (xls or xlsx) or CSV.

DataPie支持MSSQL 2008、ORACLE、ACCESS 2007数据库的EXCEL 2007导入、导出（支持多表导入同一个工作簿，支持大数据量表通过多个EXCEL工作簿导出），支持存储过程运算。

This tool is a standalone tool that will allow users to extract all embedded Open XML Format objects from a document as standalone Open XML Format files that can be opened and edited. With the release of Office 2007 came the introduction of new default file formats, called Office Open XML Formats, for Word, Excel and PowerPoint. By default, these new file formats are not backwards compatible, meaning older versions of Office cannot open, edit or create the Office Open XML Formats. To solve these compatibility issues, Microsoft released the Office Compatibility Pack, which when installed would allow users using older versions of Office to open, edit and create Office Open XML Formats. Unfortunately, the Compatibility Pack does have limitations. One major limitation is that the Compatibility Pack is unable to open and view embedded Office Open XML objects. Users who attempt to open an embedded Office Open XML using older versions of Office will be unable to do so and will receive a generic failure error. As mentioned in the following KB article, http://support.microsoft.com/kb/932121, there is no work around these users can perform without opening these files in Office 2007. This tool provides a workaround for those users who run into this issue in older versions of Office.

EPPlus is a .net library that reads and writes Excel files using the Open Office Xml format (xlsx).

ExcelPackage provides server-side generation of Excel spreadsheets

Copy Worksheets from one Excel Workbook to another.

Exports a DataTable/IEnumerable to Word / Excel / PDF / CSV / HTML / CSV Can be customized It's developed in C#

都是一些平时的积累。

The MarkLogic Toolkit for Excel allows you to quickly build content applications with MarkLogic Server that extend the functionality of Microsoft Excel and leverage Open XML (OOXML). Includes Excel Addin with supporting C#, JavaScript, and XQuery APIs

NodeXL is an Excel 2007/2010/2013 template for viewing network graphs, with a set of .NET Framework 3.5 class libraries that can be used to add network graphs

.net port of Apache POI

OfficeSVN is a subversion client for Microsoft Office 2007. This addin adds a ribbon in Word, Excel & PowerPoint.

An Excel add-in which extends the functionality of PivotTables on Analysis Services cubes and of the Excel Data Model (Power Pivot)

Speech-enhanced Office productivity solution with core components encapsulated in a single Microsoft Access file to be used by Small Businesses for Payroll calculation, automated check writing. Includes free online (Beta) version of Withholding Tax calculator 2010 (Fed/NY)

PdfReport is a code first reporting engine, which is built on top of the iTextSharp and EPPlus libraries.

PHPExcel (OLD DEAD REPOSITORY) - visit PHPOffice/PHPExcel on github instead

Framework for RAD against relational database (and xml), using a sophisticated, easy-to-use OO model (3-tier). Supports multiple database platforms. Uses generics and partial classes. Supports ADO transactions (doesnt require MSDTC). Includes a winforms Class Generatator for auto

xComp is an opensource project developed in .net. This is used to compare two excel sheets. The project is aimed to provide compare and merge features for the excel sheets. xComp is developed in C# using Visual C# 2008 Express Edition.