ClosedXML
ClosedXML is an open-source .NET library for creating, reading, and manipulating Microsoft Excel files (XLSX format) without requiring Microsoft Office to be installed. It provides a simple, intuitive API that abstracts away the complexities of the underlying Open XML SDK, allowing developers to work with Excel files using LINQ-like syntax. The library supports features such as formatting, formulas, charts, pivot tables, and data validation.
Developers should use ClosedXML when building .NET applications that need to generate or process Excel reports, export data to spreadsheets, or automate Excel-related tasks in server-side or desktop environments. It is particularly valuable in business applications, data analysis tools, and reporting systems where Excel integration is required without the overhead of Office automation or COM interop, offering better performance and reliability.