Google Summer of Code is a long-running program that supports Open Source projects. Haskell has taken part in this program almost since its inception!
It allows newcomers to open source to contribute to projects for a stipend. However, in order to do that, we need to have some ideas of what to contribute to.
In the past, this has led to many improvements for GHC, Cabal, HLS, Hasktorch… and it can include your project as well! This is a great way to find contributors for your project (even after the summer ends) – many past participants have become involved long-term.
You can find more info and instructions on how to participate here: Summer of Haskell - ideas