Multi-application projects, more frequently called umbrella projects, are how most projects are structured in a business environment, mostly because they make it easier to maintain multiple OTP Applications within a single repository. In this chapter, we’ll cover their structure, when they prove most and least useful, some subtleties of this new structure, and finally, give tips to help properly split up a monolithic library into multiple OTP Applications. Organizing Multi-App Projects One ...| Development on Adopting Erlang