First of all, I would like to thank my reviewers Samira Tasharofi, Lukas Rytz, Dominik Gruntz, Michel Schinz, Zhen Li, and Vladimir Kostyukov for their excellent feedback and valuable comments. They have shown exceptional dedication and expertise in improving the quality of this book. I would also like to thank the editors at Packt Publishing: Kevin Colaco, Sruthi Kutty, Kapil Hemnani, Vaibhav Pawar, and Sebastian Rodrigues for their help in writing this book. It was really a pleasure to work with these people.

The concurrency frameworks described in this book wouldn't have seen the light of day without a collaborative effort of a large number of people. Many individuals have, either directly or indirectly, contributed to the development of these utilities. These people are the true heroes of Scala concurrency, and they deserve thanks for Scala's excellent support for concurrent programming. It is difficult to enumerate all of them here, but I have tried my best. If somebody feels left out, he should ping me, and he'll probably appear in the next edition of this book.

It goes without saying that Martin Odersky is to be thanked for creating the Scala programming language, which was used as a platform for the concurrency frameworks described in this book. Special thanks go to him, to all the people who were a part of the Scala team at the EPFL for the last 10 or more years, and to the people at Typesafe, who are working hard to make Scala one of the best general-purpose languages out there.

Most of the Scala concurrency frameworks rely on the works of Doug Lea in one way or another. His Fork/Join framework underlies the implementation of the Akka actors, Scala Parallel collections, and the Futures and Promises library; and many of the JDK concurrent data structures described in this book are his own implementations. Many of the Scala concurrency libraries were influenced by his advice. Furthermore, I would like to thank the Java concurrency experts for the years of work they invested into making JVM a solid concurrency platform, and especially, Brian Goetz, whose book inspired our front cover.

The Scala Futures and Promises library was initially designed by Philipp Haller, Heather Miller, Vojin Jovanović, and myself, from the EPFL; Viktor Klang and Roland Kuhn from the Akka team; Marius Eriksen from Twitter; with contributions from Havoc Pennington, Rich Dougherty, Jason Zaugg, Doug Lea, and many others.

Although I was the main author of the Scala Parallel Collections, this library benefited from the input of many different people, including Phil Bagwell, Martin Odersky, Tiark Rompf, Doug Lea, and Nathan Bronson. Later on, Dmitry Petrashko and I started working on an improved version of parallel and standard collection operations, which were optimized through the use of Scala Macros. Eugene Burmako and Denys Shabalin are among the main contributors to the Scala Macros project.

The work on the Rx project was started by Erik Meijer, Wes Dyer, and the rest of the Rx team. Since its original .NET implementation, the Rx framework has been ported to many different languages, including Java, Scala, Groovy, JavaScript, and PHP, and has gained widespread adoption, thanks to the contributions and the maintenance work of Ben Christensen, Samuel Grütter, Shixiong Zhu, Donna Malayeri, and many other people.

Nathan Bronson is one of the main contributors to the ScalaSTM project, whose default implementation is based on Nathan's CCSTM project. The ScalaSTM API was designed by the ScalaSTM expert group, which comprised of Nathan Bronson, Jonas Bonér, Guy Korland, Krishna Sankar, Daniel Spiewak, and Peter Veentjer.

The initial Scala actor library was inspired by the Erlang actor model, and developed by Philipp Haller. This library inspired Jonas Bonér to start the Akka actor framework. The Akka project had many contributors, including Viktor Klang, Henrik Engström, Peter Vlugter, Roland Kuhn, Patrik Nordwall, Björn Antonsson, Rich Dougherty, Johannes Rudolph, Mathias Doenitz, Philipp Haller, and many others.

Finally, I would like to thank the entire Scala community for their contributions, and for making Scala an awesome programming language.