Writing an application that needs to connect to FTP or FTP/SSL servers? Use one of the following libraries.

Disclaimer: This site was created by developers of one of components listed below. This is why you will not find here review or detailed comparison charts of .NET components. Read The pitfalls of comparison charts blogpost by Lukas for more reasons why we don't find comparison charts helpful. In short - you have to check if the specific component is good for your specific development habits and your specific usage scenario.

.NET components

For developers working in C#, F#, VB.NET or other dotnet languages ...

Rebex FTP/SSLFTP/SSL library from creators of this site. Under continuous improvement since 2002. Runs on .NET on Windows, Linux and OS X, .NET CF, Xamarin.iOS, Xamarin.Android. Pure C# code.
CoreFTPOpen source ftp library. Looks abandoned. Last update: 2018
Dart PowerTCP FTP
FluentFTPOpensource FTP library
FTP_dotNetOpen source FTP library. Looks abandoned. Last update: 2021
FtpWebRequest classPart of .NET Framework since version 2. Many find this API a bit uneasy to use.
Chilkat FTP
Kellerman FTP Library
Limilabs Ftp.dll
nSoftware SSLAlso know as IP Works SSL component
Secure BlackboxUsed to be called Eldos Secure Blackbox. Now is owned by the /n software.
WinSCP libraryWrapper around scripting interface of popular SFTP/SCP Windows client.
Xceed FTP