Large scale haskell projects tend to have a problem with lockstep distribution of packages (especially backpack projects, being extremely granular). The unit of distribution (package) coincides with the buildable unit of code (library), and consequently each library of such an ecosystem (ex. amazonka) requires duplicate package metadata (and tests, benchmarks...).
This project aims to separate these two units by introducing multiple libraries in a single cabal package.
This proposal is based on this issue by ezyang.