Implementation

Scala
- ScalaSTM
  - A library-based Software Transactional Memory (STM) for Scala, coupled with transactional sets and maps
  - http://nbronson.github.com/scala-stm
  - https://github.com/nbronson/scala-stm
- LucreSTM
  - Extension of Scala-STM, adding optional durability layer, and providing API for confluent and reactive event layers
  - https://github.com/Sciss/LucreSTM
- akka
  - Deprecation warning Agents have been deprecated and are scheduled for removal in the next major version. We have found that their leaky abstraction (they do not work over the network) make them inferior to pure Actors, and in face of the soon inclusion of Akka Typed we see little value in maintaining the current Agents.
  - https://doc.akka.io/docs/akka/2.5.23/agents.html
Java
- jvstm
  - http://inesc-id-esw.github.io/jvstm/
  - https://github.com/inesc-id-esw/jvstm
- DeuceSTM
  - https://github.com/DeuceSTM/DeuceSTM
- stm-java
  - https://github.com/epam-mooc/stm-java
- Multiverse
  - https://github.com/pveentjer/Multiverse
Clojure
- First class supports STM by clojure runtime

Reference