I love the idea of an Airtable/Notion open source alternative, but I haven't seen any projects yet that look like a solid long-term bet.
NocoDB is neat, but looks like it's a single vendor-driven project that could go open core or die altogether if funding dries up.
Baserow also looks good, but already appears to be open core and another single-vendor project.
Undb might be a more community driven project over time. Hard to say - it looks like there's 6 contributors currently and there's not much info I could find by way of governance or company info to determine where they want to go.
Single-vendor open core (SVOC) can move quickly but it tends to degrade and disappoint over time. I would love to see a project of this sort that's actually trying to be truly community driven.
That's probably unrealistic, but I don't know if there's a ton of value in an open core solution over just using Airtable or Notion if some of the best bits are closed anyway and the fully closed alternatives are more polished and straightforward.
I'm philosophically opposed to open core (Mathesar is run out of a non-profit), but I can see why other projects do it – finding funding for a big project like this is difficult without VCs (who expect returns).