You may have seen a recent comment, looks like the main page was posted a year ago -- I relied on the URL duplicate checker when submitting it (it was new to me today to come across and I wanted to see thoughts from the HN community on it).
I ran a the search and found the previous:
A modern, concurrent web server for ruby (puma.io)
16 points by kachhalimbu 1 year ago | 2 comments | cached
I mean, this is not new at all, there is no major version that was released AFAIK...
This is great to share that though, just curious why it's on HN today? :)
Edit: typo fix.