DotVVM is an MVVM framework for ASP.NET Core and OWIN. The DotVVM project has been under active development for almost 5 years. In addition to providing some nice productivity features through MVVM development and controls, it also offers an incremental upgrade path for ASP.NET Web Forms applications through the DotVVM Adapter for ASP.NET WebForms.
I first worked with Tomáš and the DotVVM team when they participated in the .NET Summer Hackfest in 2017. The DotVVM team really jumped in, hosting a really productive in-person event with the PeachPie team in Prague.
Read more on the DotVVM project's announcement post.