ExCSS
                    
                    by: Tyler Brinks
                
                - 472 total downloads
 - Latest version: 4.3.1
 
                    ExCSS is a CSS 2.1 and CSS 3 parser for .NET. 
			ExCSS makes it easy to read and parse stylesheets into a friendly object model with full LINQ support.
                
            
                    
                        EPPlus
                    
                    by: EPPlus Software AB
                
                - 1.296k total downloads
 - Latest version: 8.2.0
 
                    A spreadsheet library for .NET framework and .NET core
                
            
                    
                        FirebirdSql.Data.FirebirdClient
                    
                    by: FirebirdSQL
                
                - 1.03k total downloads
 - Latest version: 10.3.3
 
                    Firebird ADO.NET data provider
                
            
                    
                        FastReport.OpenSource
                    
                    by: Fast Reports Inc.
                
                - 1.83k total downloads
 - Latest version: 2026.1.2
 
                    FastReport Open Source provides a free report generator for .NET/.NET Framework. You can use the FastReport Open Source in MVC, Web API, console applications.
      FastReport is written in C# and it is compatible with .NET Framework 4.6.2, .NET 6 and higher. Extendable FastReport architecture allows creating your own objects, export filters, wizards, and DB engines.
      - FastReport is a band-oriented report generator. There are 13 types of bands available: Report Title, Report Summary, Page Header, Page Footer, Column Header, Column Footer, Data Header, Data, Data Footer, Group Header, Group Footer, Child, and Overlay. In addition, sub-reports are fully supported.
      - A wide range of band types allows creating any kind of report: list, master-detail, group, multi-column, master-detail-detail and many more.
      - Wide range of available report objects: text, picture, line, shape, barcode, matrix, table, checkbox.
      - Reports can consist of several design pages, which allows reports to contain a cover, the data and a back cover, all in one file.
      - The Table object allows building a tabular report with variable number of rows and/or columns, just like in MS Excel. Aggregate functions are also available.
      - Powerful, fully configurable Matrix object that can be used to print pivot tables.
      - Report inheritance. For creating many reports with common elements such as titles, logos or footers you can place all the common elements in a base report and inherit all other reports from this base.
      Data Sources:
      - You can get data from XML, CSV, JSON, MS SQL, MySQL, Oracle, Postgres, MongoDB, Couchbase, Raven DB, SQLite.
      - FastReport has the ability to get data from business objects of IEnumerable type.
      - Report can contain data sources (tables, queries, DB connections).
      - Thus, you can not only use application-defined datasets but also connect to any database and use tables and queries directly within the report.
      FastReport Open Source can save documents in HTML, BMP, PNG, JPEG, GIF, TIFF, EMF. PDF export is available as a plugin.
                
            
                    
                        FirebaseAdmin
                    
                    by: Google Inc.
                
                - 358 total downloads
 - Latest version: 3.4.0
 
                    Firebase Admin SDK enables server-side .NET developers to integrate Firebase into their
      services and applications.
                
            
                    
                        FastReport.OpenSource.Web
                    
                    by: Fast Reports Inc.
                
                - 1.084k total downloads
 - Latest version: 2023.3.13
 
                    Package Description
                
            
                    
                        ExcelNumberFormat
                    
                    by: ExcelNumberFormat developers
                
                - 143 total downloads
 - Latest version: 1.1.0
 
                    .NET library to parse ECMA-376 number format strings and format values like Excel and other spreadsheet softwares.
                
            
                    
                        FastMember.Signed
                    
                    by: Marc Gravell
                
                - 118 total downloads
 - Latest version: 1.5.0
 
                    In .NET reflection is slow... well, kinda slow. If you need access to the members of an arbitrary type, with the type and member-names known only at runtime - then it is frankly hard (especially for DLR types). This library makes such access easy and fast.
                
            
                    
                        FastMember
                    
                    by: Marc Gravell
                
                - 162 total downloads
 - Latest version: 1.5.0
 
                    In .NET reflection is slow... well, kinda slow. If you need access to the members of an arbitrary type, with the type and member-names known only at runtime - then it is frankly hard (especially for DLR types). This library makes such access easy and fast.
                
            
                    
                        ExcelDataReader
                    
                    by: ExcelDataReader developers
                
                - 360 total downloads
 - Latest version: 3.8.0
 
                    Lightweight and fast library written in C# for reading Microsoft Excel files (XLS, XLSX).
                
            
                    
                        FastReport.Compat
                    
                    by: Fast Reports Inc.
                
                - 836 total downloads
 - Latest version: 2026.1.2
 
                    Common compatible types for FastReport .Net, Core and Mono
                
            
                    
                        FastExpressionCompiler.src
                    
                    by: Maksim Volkau
                
                - 270 total downloads
 - Latest version: 5.3.3
 
                    FastExpressionCompiler is 10-40x times faster than Expression.Compile()
                
            
                    
                        ErrorOr
                    
                    by: Amichai Mantinband
                
                - 59 total downloads
 - Latest version: 2.0.1
 
                    A simple, fluent discriminated union of an error or a result.
                
            
                    
                        ExtendedNumerics.BigDecimal
                    
                    by: Adam White  Jan Christoph Bernack  Rick Harker
                
                - 260 total downloads
 - Latest version: 3001.1.0.233
 
                    An arbitrary precision decimal (base 10) floating point number type using a mantissa and exponent. Supports nth roots, trigonometric functions, logarithms, natural e, pi, etc.
                
            
                    
                        ExcelDataReader.DataSet
                    
                    by: ExcelDataReader developers
                
                - 90 total downloads
 - Latest version: 3.8.0
 
                    ExcelDataReader extension for reading Microsoft Excel files into System.Data.DataSet.
                
            
                    
                        Fare
                    
                    by: Nikos Baxevanis
                
                - 141 total downloads
 - Latest version: 2.2.1
 
                    .NET port of dk.brics.automaton - Project Fare is an effort to bring a DFA/NFA (finite-state automata) implementation from Java to .NET. There are quite a few implementations available in other languages today. This project aims to fill the gap in .NET.
                
            
                    
                        Esprima
                    
                    by: Sebastien Ros
                
                - 219 total downloads
 - Latest version: 3.0.5
 
                    Standard-compliant ECMAScript 2022 parser (also known as JavaScript).
                
            
                    
                        EPPlus.Interfaces
                    
                    by: EPPlus.Interfaces
                
                - 120 total downloads
 - Latest version: 8.1.0
 
                    Package Description
                
            
                    
                        Fizzler
                    
                    by: Atif Aziz  Colin Ramsay
                
                - 168 total downloads
 - Latest version: 1.3.1
 
                    Fizzler is a W3C Selectors parser and generic selector framework for document hierarchies.
                
            
                    
                        EPPlus.System.Drawing
                    
                    by: EPPlus.System.Drawing
                
                - 129 total downloads
 - Latest version: 8.1.0
 
                    Package Description