[donri]

HAppS is dead, long live Happstack!

What you're talking about was the HAppS-State component of the HAppS application server, a project which is in deed not active anymore. Happstack is the active fork of HAppS and had a "happstack-state" component for a while, but this was eventually rewritten from scratch and made independent of Happstack and is now known as acid-state [1]. It's even used for the new Hackage server that powers the Haskell package ecosystem.

[1] https://github.com/acid-state/acid-state