In our recent research and development (R&D) project we dive deep into event sourcing. We are building a set of independent applications that produces a stream of events that are stored in a specialized stream database (we are evaluating Event Store). The events will form a kind of a log and the state of data will then be derived from that log by building specialized views on that stream of events. This view is called projection. What we are doing here is we are making use of CQRS pattern. We are separating the command from a query as in Command Query Responsibility Segregation (CQRS). The responsibility is segregated between the stream of commands (events) and a set of queries (projections).
Our R&D projects are as usual combining an interesting business opportunity with a new technology we would like to test. It surely looks like in that case it would make a product. But who knows! We will keep you posted.