event management
venueless has a nice setup of tool combinations
BSL license: only for non-production use with Additional Use Grant - but readme FAQ says:
You can set up venueless on a server under your control to host as many events as you like without any limitations, but you can't provide it as a service to other organizations.
install with docker, requires redis & pg: https://github.com/venueless/venueless/blob/dev/docs/admin/management.rst