nginx / ngx_cache_purge (project fully funded by yo.se)
Module adding ability to purge content from nginx's FastCGI, proxy, SCGI and uWSGI caches.

nginx / ngx_coolkit
Collection of small and useful nginx add-ons.

nginx / ngx_postgres
Upstream module that allows nginx to communicate directly with PostgreSQL database.

nginx / ngx_slowfs_cache (project fully funded by c2hosting.com)
Module adding ability to cache static files.

nginx / ngx_supervisord (project fully funded by megiteam.pl)
Module providing nginx with API to communicate with supervisord and manage (start/stop) backends on-demand.