Looks like it’s a good mission, but I have no idea what it actually is and what they do or what it’s meant to be beyond a collection of ideals.
In short the IndieWeb tries to maintain your identity through all different social media, websites, services and whatnot you are using by connecting them to your personal domain. This way you maintain ownership of the content and other people can read your content and interact with you in their different platforms.
One of the main features of IndieWeb is POSSE (Publish on your Own Site, Syndicate Elsewhere). I haven’t tried it yet but seems a good approach.
I found this article to give a very good overview of the IndieWeb project: