ArchiSteamFarm
C# application with primary purpose of farming Steam cards
...Unlike Idle Master which works only for one account at a given time, while requiring Steam client running in the background and launching additional processes imitating "game-playing" status, ASF doesn't require any Steam client running in the background, doesn't launch any additional processes and is made to handle unlimited Steam accounts at once. In addition to that, it's meant to be run on servers or other desktop-less machines and features full cross-OS support, which makes it possible to launch on any operating system with .NET Core runtime, such as Windows, Linux, and macOS. ASF is possible thanks to the gigantic amount of work done in the marvelous SteamKit2 library. Today, ASF is one of the most versatile Steam power tools, allowing you to make use of many features that were implemented over time.