A while ago, I wrote a post about the multiton pattern on server side that utilizes a fixed amount of computation resource to serve a large number of concurrent requests for the same representation that needs to be generated on demand. The pattern helps to avoid racing condition that the concurrent request processing could lead to.
Each resource instance in the registry or map works like a proxy. The proxy's interface is the same for the consumers no matter it arrives early or late. Inside the proxy, the representation is produced on demand, or retrieved from a cache or a persistent copy.
A client side multition can reduce not only client side load but also the server side load and the traffic between client and server. Consider a client side JS component that depends on a remote resource. When loading, the component will issue an AJAX call to the remote resource and render when the resource representation is available. A problem arises when there are many such component instances on a page targeting the same remote resource. The server side will see multiple concurrent requests of the same resource representation when the client loads such a page. That will make backend services busy for a while. While a server side multition can help, a client side multition will further reduce the client side load on a page and also reduce the connection numbers and network traffic to the server.