concurrent.cr alternatives and similar shards

Based on the "Processes and Threads" category.
Alternatively, view concurrent.cr alternatives based on common mentions on social networks and blogs.

• await_async

  8.1 0.0 concurrent.cr VS await_async

  Provide await and async methods to Crystal Lang

• werk

  4.4 6.1 concurrent.cr VS werk

  Dead simple task runner

Do you think we are missing an alternative of concurrent.cr or a related project?