Hey! Mailspring maintainer here—could you elaborate on the "open core model"? I'm not sure I follow. If it'd generate more than $~10k/mo in revenue and would allow me and others at F376 to sustainably work on Mailspring indefinitely, it might be a great alternative to the Mailspring ID and pro features.

Open core is generally a base free (as in speech and beer) version, and extended version/plugins that aren't. See Sidekiq and Hashicorp's products.

It's about selling non-free software on top of some free base.