Assetyard
Assetyard is cross-platform desktop Content Pipeline for game projects.
What is the Content Pipeline?
Games from Within describes the Content Pipeline as
... the path that all the game assets follow, from conception until they can be loaded in the game. Game assets include everything that is not code: models, textures, materials, sounds, animations, cinematics, scripts, etc. During their trip through the pipeline, assets might be converted, optimized, chopped to bits, or combined. In the end, the asset is in a format that will be shipped with the final version of the game.
Xamarin describes the Content Pipeline as
... a general term for the process of converting a file from one format to another. The input of the content pipeline is typically a file outputted by an authoring tool, such as image files from Photoshop. The content pipeline creates the output file in a format that can be loaded directly by a game project. Typically the output files are optimized for fast loading and reduced disk size.
Why use a Content Pipeline?
See Xamarin's documention: Why Use a Content Pipeline?