Navigating .NET library licensing changes.
Recent .NET ecosystem licensing changes impact several libraries, requiring projects to either pay for a license or find an alternative. Welcome to the FOSSED, where we will help you navigate the changes and find free open-source alternatives.
Affected Libraries
Moq
The popular mocking library for .NET
FluentAssertions
A set of .NET extension methods for assertions
AutoMapper
A convention-based object-object mapper
MediatR
Simple mediator implementation in .NET
MassTransit
Distributed application framework for .NET
ImageSharp
Cross-platform image processing library for .NET
Latest News
View All News →- 2025-04-05
Milan Jovanović: MediatR and MassTransit Going Commercial: What This Means For You
Big changes are happening in the .NET ecosystem. Three powerhouse libraries - MediatR, AutoMapper, and MassTransit - are moving to commercial licenses. Not so long ago, Fluent Assertions also announced its plans to move to a commercial license.mediatrmasstransitautomapper - 2025-04-03
Announcing MassTransit v9
With MassTransit v9, we are transitioning to a commercial licensing model. This change ensures long-term sustainability, continued innovation, and enterprise-grade support — while leaving MassTransit v8 open-source and available to the community.masstransit - 2025-04-02
Jimmy Bogard: AutoMapper and MediatR Going Commercial
In order to ensure the long-term sustainability of my OSS projects, I will be commercializing AutoMapper and MediatR.automappermediatr
FAQ
Tell me about this website
This website is a resource hub for developers seeking to understand and manage open-source licenses. It offers information on various licenses, their usage, and project management. The goal is to provide the reasoning behind licenses, enabling informed decisions. It does not discourage paid licenses but aims to foster understanding for better choices. This website is an independent project by a single developer and is not affiliated with any specific license.
Library X has gone commercial. What are my options?
Don't panic! 😎 First, review the pricing and consider paying if you value the library and plan to continue using it. Often, you can stick with the last free version by pinning its version. If the license permits, forking the library for personal maintenance is another option. Finally, explore open-source alternatives.
Why is there negative sentiment towards some libraries that have become commercial?
Negative sentiment towards commercializing libraries arises mainly from how it's done. Moq's secret email collection and network calls via SponsorLink caused backlash. FluentAssertions' abrupt, costly license change also drew criticism, including questions about past contributions. Key issues are: lack of transparency, sudden changes, questionable privacy (Moq), and perceived disrespect. Positive examples like MassTransit's clear versioning and future plans, ImageSharp's fair dual-licensing, and Jimmy Bogard's (MediatR, AutoMapper) transparent, non-punitive approach show that clear communication, grandfathering, and community respect lead to better reception. The process of commercialization must be handled carefully to avoid negative reactions.
How can I contribute to this project?
If you'd like to propose changes, add information, or contribute in any way to the project, please visit the GitHub repository at https://github.com/dariusz-wozniak/fossed. There, you can create issues for suggestions or problems, or create a pull request. All contributions are welcome and appreciated!