Developer Enviroments News Today

I have been using Nix for almost four years and also maintaining some packages at nixpkgs (the primary Nix repository). The Nix learning curve is complicated, so I could not get my colleagues into it. But Devenv made it so easy to compose a developer environment, so I got their attraction, and some of them switched already, and we are looking to where we can use it too. What is Devenv?