ExCSS by: Tyler Brinks

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.

ExtendedNumerics.BigDecimal by: Adam White, Jan Christoph Bernack, Rick Harker

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.

FastEndpoints.Swagger by: FastEndpoints

Swagger support for FastEndpoints.

fasterflect by: Buu Nguyen, Morten Mertner

.NET library that improves your productivity and application performance when performing reflection operations. It allows you to perform metadata lookup and reflection invocation intuitively while achieving greater performance than the built-in .NET Reflection.

FastExpressionCompiler.src by: Maksim Volkau

FastExpressionCompiler is 10-40x times faster than Expression.Compile()

FastMember by: Marc Gravell

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.Signed by: Marc Gravell

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.

FFMpegCore by: Vlad Jerca, Malte Rosenbjerg

A great way to use FFMpeg encoding when writing video applications, client-side and server-side. It has wrapper methods that allow conversion to all web formats: MP4, OGV, TS and methods of capturing screens from the videos.

FirebaseAdmin by: Google Inc.

Firebase Admin SDK enables server-side .NET developers to integrate Firebase into their services and applications.

Fizzler by: Atif Aziz, Colin Ramsay

Fizzler is a W3C Selectors parser and generic selector framework for document hierarchies.

FluentScheduler by: Jim Geurts <jim@biacreations.com>, Talles L <talleslasmar@gmail.com> & further contributors

Automated job scheduler with fluent interface.

FluentValidation by: Jeremy Skinner

A validation library for .NET that uses a fluent interface to construct strongly-typed validation rules.

FluentValidation.Mvc5 by: Jeremy Skinner

ASP.NET MVC 5 integration for FluentValidation

FluentValidation.ValidatorAttribute by: Jeremy Skinner

A validation library for .NET that uses a fluent interface to construct strongly-typed validation rules.

Flurl by: Todd Menier

A fluent, portable URL builder. To make HTTP calls off the fluent chain, check out Flurl.Http.

Flurl.Http by: Todd Menier

A fluent, portable, testable HTTP client library.

GhostScriptSharp by: https://github.com/mephraim/ghostscriptsharp/

A very simple .NET wrapper for Ghostscript 1.1 pdf conversion toolkit

Google.Api.CommonProtos by: Google LLC

Common Protocol Buffer messages for Google APIs

Google.Api.Gax by: Google Inc.

Support classes for Google API client libraries

Google.Api.Gax.Grpc by: Google Inc.

Additional support classes for Google gRPC API client libraries