Quire is a hierarchical task management tool built for teams that need to break large projects into deeply nested subtasks — its infinite nested list structure lets teams decompose complex work to any level of granularity without losing the overview. Founded in 2014, Quire's Sublime View filters the full task tree down to a focused list for daily execution, while its kanban board handles sprint-style delivery. Its generous free tier and clean interface make it popular with non-profit organizations and distributed volunteer teams.

Reference:

Quire on Wikipedia

https://quire.io