I’ve had the privilege to interact directly with Willy (the main developer for many years, still the project lead) on the mailing list, in person at the conference, and even though I’ve never paid a dime, the interaction has been the best open-source experience I’ve ever had. Willy routinely writes multi-paragraph responses on the mailing list to my hair-brained suggestions for how HAProxy could be better for my company’s rather unique needs.
I often feel bad that I cannot do more for the project, because it is so well thought-through and delivered.
The software cuts no corners and delivers at fractions of the TCO of competition (limited by my opinion and experience, of course). For instance, just last week, I spun a rate limiting solution in half a morning, that mitigated some annoying proxy bots instantly (and is flexible enough to automatically block offenders without affecting legitimate users).
The stats, DNS support, and integrations and many other featured are second to none among other load balancers.
It’s an impressive and refreshing project. We could all learn something from HAProxy and the team.