2. AcliAction Cable command-line client
6. WsdirectorAll the world's a server, and all the men and women merely clients
10. Active deliveryRuby framework for keeping all types of notifications (mailers, push notifications, whatever) in one place
11. IsolatorDetect non-atomic interactions within DB transactions
13. LitecableLightweight Action Cable implementation (Rails-free)
19. engemsRails component-based architecture on top of engines and gems (showroom)