If you're unfamiliar with Firebird, it's an open-source, cross-platform, client/server Relational Database Management System (RDMS). A brief intro here: https://www.firebirdnews.org/docs/fb2min.html
How is it that it's so little known among developers?
If you use it or have used it in the past, what is your opinion of it?
Last October I went to the Firebird Conference in Berlin. It's true that the community is fairly small and does not attract a lot of new blood. There are however some very knowledgeable people there who've been around often since day 1. From what I've heard, it's hard to say much about the number of deployments, because it just keeps working, and (not having a reason to) users don't reach out. Most came from InterBase, decades ago. Supposedly software provided by the Russian tax office uses Firebird Embedded...? That adds up rather quickly already. It's unfortunate that nowadays few consider it. Desktop software taking the backseat and the abundance of alternatives play a role in that. The slow development pace is good for stability, but otherwise doesn't help either.
*I flipped a single bit in my Firebird distribution to have the server process set an exclusive read lock in addition to its exclusive write lock, so that an open database can't be copied—the only thing that could go wrong.
For smaller sites with hundreds of users it does everything you could ask. It's very easy to manage - a single DB file. It has a great admin tool available - IB Expert, as good as TOAD in most ways.
Probably hits some limits if you're looking at very high transaction loads (>1000TPS), or very large (multi TB) but really for every day use you can't do better.
It used to be owned by Borland, I believe, but open source now. It has strong ties to the Delphi community and is very easy to use from there.
Edit: And yes like you I don't understand why its not well known. Probably a victim of Borland anti-marketing
> How is it that it's so little known among developers?
Both Interbase and, by extension, Firebird were part of the Borland's and, later, Embarcadero's product ecosystem (especially, Delphi and C++ Builder) and, thus, closely tied to relevant developer community, as chadcmulligan mentioned. As the overall ecosystem declined, so did the popularity and use of Interbase and Firebird.