pybossa (code) is F/OSS for organizing crowdsourcing groups. Whether you're working on PDFs, gathering or filtering data, or localization of various forms, pybossa makes it easy to gather work, hand it out, and let people report results.
PYBOSSA has an impressive list of projects it was used on as well which is worth perusing; from national libraries to newspapers and editorial efforts and public health. PYBOSSA is chock full of features.
PYBOSSA provides quick start documentation but unfortunately it's not so
docker friendly. This means that going through the installation process is a bit manual and dependencies are installed on the host machine.