evma_httpserver is definitely an alternative and one we used early on at PR. Having said that, we migrated away from it because it didn't provide us with the flexibility we needed to do keepalive, pipelining, etc - it basically provides just a very thin layer on top of an EM connection, hence the minimal API and functionality.

Thin would be an alternative to Goliath as well, although we chose to switch to a different parser and also to add the Fiber logic/wrappers right into the framework.

The way I think about it is: if Thin is an app server, then Goliath is more of a minimal framework which you can use to go from start to finish in if you need to bring up an API endpoint. That includes, configuration, routing if you need it, validation, etc.