I coded SackFix in 2016 and 2017 to learn Scala and AKKA with a real world spec. It took many months and was coded in 60 minute gaps between real life. Having said that I focused in the last few months and tidied up some of the issues.
It has all the most obvious features of a fix implementation, hope it is used/useful. I intend to move onto a more interesting personal project now.
It is released under the MIT license, so please download it and change it as you need to.
Jonathan April 2017
ps Updated in 2021 to Scala 2.13 and akka.typed. The biggest issue faced was the interaction between akka.typed and the classic actor for TCP which they have not migrated.