This is the first 853 specific release! It requires at least the Notes/Domino 8.5.3 managed beta, also known as "CD5". Do not install it on a 8.5.2 server as it uses some new 8.5.3 capabilities and will fail on an 8.5.2 server.
So this release contains all what the 8.5.2 release contains, plus an implementation of the new Domino standalone REST services! Once installed, and the server properly configured (see the pdf included in the zip file), you can emit REST requests to the server and get back views and documents as JSON objects, without having to define anything else. Note that the code is shared with the XPages REST service control, if you want an easy customization experience.
Included in the zip file is a complete documentation for the services, which should get you started quickly. Some enablement material, like a video, is also available from the main openNTF site.
Please, give us your feedback! REST services is a very important part of our application development strategy, and the team wants to hear from you.