All these products are designed to work with each other, and support innovation across all the products. The connections are all open, and all the parts are replaceable. You can generate compatible feeds with any blogging environment or content management system. The extensions to RSS we're using are all documented in the new source namespace. Any aggregator can produce the JSON files that River4 generates, that are designed to plug into RiverBrowser.
If you've been following my development process, this is the cap, where it all comes together in a simple neat package anyone can use. You don't have to understand all of the tools behind it, you don't have to understand any of them, actually. It's just useful and usable as-is