We use Informix too! Well, our customers do. Thought we were a dying breed. Surprised to see it mentioned here twice. We use Postgres and MySQL too.
Nice to see there are still some Informix users alive! :) We are dying breed for sure, don't see any new solutions being developed lately. Too bad. Anyhoo, we also use Oracle, MS SQL and MySQL.
We/Our customers also use informix. We also use postgres a little bit too. The company was a startup about 15 years ago. Actually, looking at your past comments, looks like we may work at the same company.