From the project page: "Simplify allows particular fields to be hidden from the user interface. This helps to de-clutter forms and present a more user-friendly experience to content editors..."

Lets sites talk to each other. REST.

Rabbit Hole is a module that adds the ability to control what should happen when an entity is being viewed at its own page.

Also see Internal Nodes

Edit all items in a menu in one place.

Replaces administrative overview/listing pages with Views, including Views Bulk Operations.

This module should not be enabled in production environments. These views should be used as starting points or examples only and should be exported and used in custom modules if they are to be used in a production environment.

This module redirects to a user login when a user hits a page they do not have access to.

Get autocomplete working for views exposed filters. From the project page: Add autocomplete functionality to the views filter text fields. It works for node titles or cck text fields. The autocomplete results are actually the view results, so they are view related. How to use it: (New) Video Tutorial : http://codekarate.com/daily-dose-of-drupal/drupal-7-views-autocomplete-filter

Used on http://drupal.org, "This module stores the changes of a node into a field attached to comments allowing to display a kind-of activity stream on the node much like on drupal.org issues just with a lot less custom code."

There is a great article that shows how all of the Acquia sites are architected. In that article, it is mentioned that Services is used quite a bit to power REST endpoints. Here is a really, really, useful tidbit that I don't want to forget which comes from that article.

Schedule a time when a particular revision should go live.