diff --git a/akka-actor-tests/src/test/scala/akka/actor/ActorWithStashSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/ActorWithStashSpec.scala
index 9bf7ff714b..2a5728bb85 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/ActorWithStashSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/ActorWithStashSpec.scala
@@ -149,7 +149,7 @@ class ActorWithStashSpec extends AkkaSpec with DefaultTimeout with BeforeAndAfte
       val restartLatch = new TestLatch
       val hasMsgLatch = new TestLatch
 
-      val slaveProps = Props(new Actor with Stash {
+      val employeeProps = Props(new Actor with Stash {
         def receive = {
           case "crash" =>
             throw new Exception("Crashing...")
@@ -169,10 +169,10 @@ class ActorWithStashSpec extends AkkaSpec with DefaultTimeout with BeforeAndAfte
           super.preRestart(reason, message)
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
-      slave ! "hello"
-      slave ! "crash"
+      employee ! "hello"
+      employee ! "crash"
 
       Await.ready(restartLatch, 10 seconds)
       Await.ready(hasMsgLatch, 10 seconds)
diff --git a/akka-actor-tests/src/test/scala/akka/actor/RestartStrategySpec.scala b/akka-actor-tests/src/test/scala/akka/actor/RestartStrategySpec.scala
index 780a69504b..0620759893 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/RestartStrategySpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/RestartStrategySpec.scala
@@ -31,7 +31,7 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
 
   "A RestartStrategy" must {
 
-    "ensure that slave stays dead after max restarts within time range" in {
+    "ensure that employee stays dead after max restarts within time range" in {
       val boss = system.actorOf(
         Props(
           new Supervisor(OneForOneStrategy(maxNrOfRetries = 2, withinTimeRange = 1 second)(List(classOf[Throwable])))))
@@ -41,7 +41,7 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
       val countDownLatch = new TestLatch(3)
       val stopLatch = new TestLatch
 
-      val slaveProps = Props(new Actor {
+      val employeeProps = Props(new Actor {
 
         def receive = {
           case Ping  => countDownLatch.countDown()
@@ -59,32 +59,32 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
           stopLatch.open()
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
-      slave ! Ping
-      slave ! Crash
-      slave ! Ping
+      employee ! Ping
+      employee ! Crash
+      employee ! Ping
 
       // test restart and post restart ping
       Await.ready(restartLatch, 10 seconds)
 
       // now crash again... should not restart
-      slave ! Crash
-      slave ! Ping
+      employee ! Crash
+      employee ! Ping
 
       Await.ready(secondRestartLatch, 10 seconds)
       Await.ready(countDownLatch, 10 seconds)
 
-      slave ! Crash
+      employee ! Crash
       Await.ready(stopLatch, 10 seconds)
     }
 
-    "ensure that slave is immortal without max restarts and time range" in {
+    "ensure that employee is immortal without max restarts and time range" in {
       val boss = system.actorOf(Props(new Supervisor(OneForOneStrategy()(List(classOf[Throwable])))))
 
       val countDownLatch = new TestLatch(100)
 
-      val slaveProps = Props(new Actor {
+      val employeeProps = Props(new Actor {
 
         def receive = {
           case Crash => throw new Exception("Crashing...")
@@ -94,16 +94,16 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
           countDownLatch.countDown()
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
       (1 to 100).foreach { _ =>
-        slave ! Crash
+        employee ! Crash
       }
       Await.ready(countDownLatch, 2 minutes)
-      assert(!slave.isTerminated)
+      assert(!employee.isTerminated)
     }
 
-    "ensure that slave restarts after number of crashes not within time range" in {
+    "ensure that employee restarts after number of crashes not within time range" in {
       val boss = system.actorOf(Props(
         new Supervisor(OneForOneStrategy(maxNrOfRetries = 2, withinTimeRange = 500 millis)(List(classOf[Throwable])))))
 
@@ -113,7 +113,7 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
       val pingLatch = new TestLatch
       val secondPingLatch = new TestLatch
 
-      val slaveProps = Props(new Actor {
+      val employeeProps = Props(new Actor {
 
         def receive = {
           case Ping =>
@@ -135,16 +135,16 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
           }
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
-      slave ! Ping
-      slave ! Crash
+      employee ! Ping
+      employee ! Crash
 
       Await.ready(restartLatch, 10 seconds)
       Await.ready(pingLatch, 10 seconds)
 
-      slave ! Ping
-      slave ! Crash
+      employee ! Ping
+      employee ! Crash
 
       Await.ready(secondRestartLatch, 10 seconds)
       Await.ready(secondPingLatch, 10 seconds)
@@ -153,15 +153,15 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
       sleep(700L)
 
       // now crash again... should and post restart ping
-      slave ! Crash
-      slave ! Ping
+      employee ! Crash
+      employee ! Ping
 
       Await.ready(thirdRestartLatch, 1 second)
 
-      assert(!slave.isTerminated)
+      assert(!employee.isTerminated)
     }
 
-    "ensure that slave is not restarted after max retries" in {
+    "ensure that employee is not restarted after max retries" in {
       val boss = system.actorOf(Props(new Supervisor(OneForOneStrategy(maxNrOfRetries = 2)(List(classOf[Throwable])))))
 
       val restartLatch = new TestLatch
@@ -169,7 +169,7 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
       val countDownLatch = new TestLatch(3)
       val stopLatch = new TestLatch
 
-      val slaveProps = Props(new Actor {
+      val employeeProps = Props(new Actor {
 
         def receive = {
           case Ping  => countDownLatch.countDown()
@@ -186,33 +186,33 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
           stopLatch.open()
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
-      slave ! Ping
-      slave ! Crash
-      slave ! Ping
+      employee ! Ping
+      employee ! Crash
+      employee ! Ping
 
       // test restart and post restart ping
       Await.ready(restartLatch, 10 seconds)
 
-      assert(!slave.isTerminated)
+      assert(!employee.isTerminated)
 
       // now crash again... should not restart
-      slave ! Crash
-      slave ! Ping
+      employee ! Crash
+      employee ! Ping
 
       Await.ready(secondRestartLatch, 10 seconds)
       Await.ready(countDownLatch, 10 seconds)
 
       sleep(700L)
 
-      slave ! Crash
+      employee ! Crash
       Await.ready(stopLatch, 10 seconds)
       sleep(500L)
-      assert(slave.isTerminated)
+      assert(employee.isTerminated)
     }
 
-    "ensure that slave is not restarted within time range" in {
+    "ensure that employee is not restarted within time range" in {
       val restartLatch, stopLatch, maxNoOfRestartsLatch = new TestLatch
       val countDownLatch = new TestLatch(2)
 
@@ -224,7 +224,7 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
         }
       }))
 
-      val slaveProps = Props(new Actor {
+      val employeeProps = Props(new Actor {
 
         def receive = {
           case Ping  => countDownLatch.countDown()
@@ -239,32 +239,32 @@ class RestartStrategySpec extends AkkaSpec with DefaultTimeout {
           stopLatch.open()
         }
       })
-      val slave = Await.result((boss ? slaveProps).mapTo[ActorRef], timeout.duration)
+      val employee = Await.result((boss ? employeeProps).mapTo[ActorRef], timeout.duration)
 
-      slave ! Ping
-      slave ! Crash
-      slave ! Ping
+      employee ! Ping
+      employee ! Crash
+      employee ! Ping
 
       // test restart and post restart ping
       Await.ready(restartLatch, 10 seconds)
 
-      assert(!slave.isTerminated)
+      assert(!employee.isTerminated)
 
       // now crash again... should not restart
-      slave ! Crash
+      employee ! Crash
 
       // may not be running
-      slave ! Ping
+      employee ! Ping
       Await.ready(countDownLatch, 10 seconds)
 
       // may not be running
-      slave ! Crash
+      employee ! Crash
 
       Await.ready(stopLatch, 10 seconds)
 
       Await.ready(maxNoOfRestartsLatch, 10 seconds)
       sleep(500L)
-      assert(slave.isTerminated)
+      assert(employee.isTerminated)
     }
   }
 }
diff --git a/akka-actor/src/main/scala/akka/io/Inet.scala b/akka-actor/src/main/scala/akka/io/Inet.scala
index 0597ab96fa..ce6654e3f8 100644
--- a/akka-actor/src/main/scala/akka/io/Inet.scala
+++ b/akka-actor/src/main/scala/akka/io/Inet.scala
@@ -35,8 +35,7 @@ object Inet {
     def beforeConnect(@unused s: Socket): Unit = ()
 
     /**
-     * Action to be taken for this option after connect returned (i.e. on
-     * the slave socket for servers).
+     * Action to be taken for this option after connect returned.
      */
     def afterConnect(@unused s: Socket): Unit = ()
   }
@@ -50,20 +49,17 @@ object Inet {
   trait SocketOptionV2 extends SocketOption {
 
     /**
-     * Action to be taken for this option after connect returned (i.e. on
-     * the slave socket for servers).
+     * Action to be taken for this option after connect returned.
      */
     def afterBind(@unused s: DatagramSocket): Unit = ()
 
     /**
-     * Action to be taken for this option after connect returned (i.e. on
-     * the slave socket for servers).
+     * Action to be taken for this option after connect returned.
      */
     def afterBind(@unused s: ServerSocket): Unit = ()
 
     /**
-     * Action to be taken for this option after connect returned (i.e. on
-     * the slave socket for servers).
+     * Action to be taken for this option after connect returned.
      */
     def afterConnect(@unused s: DatagramSocket): Unit = ()
 
diff --git a/akka-docs/src/main/paradox/stream/stream-substream.md b/akka-docs/src/main/paradox/stream/stream-substream.md
index 13026497b8..9805d06cce 100644
--- a/akka-docs/src/main/paradox/stream/stream-substream.md
+++ b/akka-docs/src/main/paradox/stream/stream-substream.md
@@ -54,9 +54,9 @@ Java
 ![stream-substream-groupBy2.png](../../images/stream-substream-groupBy2.png)
 
 Also substreams, more precisely, `SubFlow` and `SubSource` have methods that allow you to
-merge or concat substreams into the master stream again.
+merge or concat substreams into the main stream again.
 
-The `mergeSubstreams` method merges an unbounded number of substreams back to the master stream.
+The `mergeSubstreams` method merges an unbounded number of substreams back to the main stream.
 
 Scala
 :   @@snip [SubstreamDocSpec.scala](/akka-docs/src/test/scala/docs/stream/SubstreamDocSpec.scala) { #groupBy3 }
diff --git a/akka-remote-tests/src/multi-jvm/scala/akka/remote/LookupRemoteActorSpec.scala b/akka-remote-tests/src/multi-jvm/scala/akka/remote/LookupRemoteActorSpec.scala
index d7e07d85cc..c7a961f917 100644
--- a/akka-remote-tests/src/multi-jvm/scala/akka/remote/LookupRemoteActorSpec.scala
+++ b/akka-remote-tests/src/multi-jvm/scala/akka/remote/LookupRemoteActorSpec.scala
@@ -21,8 +21,8 @@ class LookupRemoteActorMultiJvmSpec(artery: Boolean) extends MultiNodeConfig {
       akka.remote.artery.enabled = $artery
       """)).withFallback(RemotingMultiNodeSpec.commonConfig))
 
-  val master = role("master")
-  val slave = role("slave")
+  val leader = role("leader")
+  val follower = role("follower")
 
 }
 
@@ -49,19 +49,19 @@ abstract class LookupRemoteActorSpec(multiNodeConfig: LookupRemoteActorMultiJvmS
 
   def initialParticipants = 2
 
-  runOn(master) {
+  runOn(leader) {
     system.actorOf(Props[SomeActor](), "service-hello")
   }
 
   "Remoting" must {
     "lookup remote actor" taggedAs LongRunningTest in {
-      runOn(slave) {
+      runOn(follower) {
         val hello = {
-          system.actorSelection(node(master) / "user" / "service-hello") ! Identify("id1")
+          system.actorSelection(node(leader) / "user" / "service-hello") ! Identify("id1")
           expectMsgType[ActorIdentity].ref.get
         }
         hello.isInstanceOf[RemoteActorRef] should ===(true)
-        val masterAddress = testConductor.getAddressFor(master).await
+        val masterAddress = testConductor.getAddressFor(leader).await
         (hello ? "identify").await.asInstanceOf[ActorRef].path.address should ===(masterAddress)
       }
       enterBarrier("done")
diff --git a/akka-remote-tests/src/multi-jvm/scala/akka/remote/NewRemoteActorSpec.scala b/akka-remote-tests/src/multi-jvm/scala/akka/remote/NewRemoteActorSpec.scala
index 0d0595820e..f34a8bb7c1 100644
--- a/akka-remote-tests/src/multi-jvm/scala/akka/remote/NewRemoteActorSpec.scala
+++ b/akka-remote-tests/src/multi-jvm/scala/akka/remote/NewRemoteActorSpec.scala
@@ -24,16 +24,16 @@ class NewRemoteActorMultiJvmSpec(artery: Boolean) extends MultiNodeConfig {
       akka.remote.use-unsafe-remote-features-outside-cluster = on
       """).withFallback(RemotingMultiNodeSpec.commonConfig)))
 
-  val master = role("master")
-  val slave = role("slave")
+  val leader = role("leader")
+  val follower = role("follower")
 
-  deployOn(master, """
-    /service-hello.remote = "@slave@"
-    /service-hello-null.remote = "@slave@"
-    /service-hello3.remote = "@slave@"
+  deployOn(leader, """
+    /service-hello.remote = "@follower@"
+    /service-hello-null.remote = "@follower@"
+    /service-hello3.remote = "@follower@"
     """)
 
-  deployOnAll("""/service-hello2.remote = "@slave@" """)
+  deployOnAll("""/service-hello2.remote = "@follower@" """)
 }
 
 class NewRemoteActorMultiJvmNode1 extends NewRemoteActorSpec(new NewRemoteActorMultiJvmSpec(artery = false))
@@ -69,14 +69,14 @@ abstract class NewRemoteActorSpec(multiNodeConfig: NewRemoteActorMultiJvmSpec)
   "A new remote actor" must {
     "be locally instantiated on a remote node and be able to communicate through its RemoteActorRef" in {
 
-      runOn(master) {
+      runOn(leader) {
         val actor = system.actorOf(Props[SomeActor](), "service-hello")
         actor.isInstanceOf[RemoteActorRef] should ===(true)
-        actor.path.address should ===(node(slave).address)
+        actor.path.address should ===(node(follower).address)
 
-        val slaveAddress = testConductor.getAddressFor(slave).await
+        val followerAddress = testConductor.getAddressFor(follower).await
         actor ! "identify"
-        expectMsgType[ActorRef].path.address should ===(slaveAddress)
+        expectMsgType[ActorRef].path.address should ===(followerAddress)
       }
 
       enterBarrier("done")
@@ -84,14 +84,14 @@ abstract class NewRemoteActorSpec(multiNodeConfig: NewRemoteActorMultiJvmSpec)
 
     "be locally instantiated on a remote node (with null parameter) and be able to communicate through its RemoteActorRef" in {
 
-      runOn(master) {
+      runOn(leader) {
         val actor = system.actorOf(Props(classOf[SomeActorWithParam], null), "service-hello-null")
         actor.isInstanceOf[RemoteActorRef] should ===(true)
-        actor.path.address should ===(node(slave).address)
+        actor.path.address should ===(node(follower).address)
 
-        val slaveAddress = testConductor.getAddressFor(slave).await
+        val followerAddress = testConductor.getAddressFor(follower).await
         actor ! "identify"
-        expectMsgType[ActorRef].path.address should ===(slaveAddress)
+        expectMsgType[ActorRef].path.address should ===(followerAddress)
       }
 
       enterBarrier("done")
@@ -99,24 +99,24 @@ abstract class NewRemoteActorSpec(multiNodeConfig: NewRemoteActorMultiJvmSpec)
 
     "be locally instantiated on a remote node and be able to communicate through its RemoteActorRef (with deployOnAll)" in {
 
-      runOn(master) {
+      runOn(leader) {
         val actor = system.actorOf(Props[SomeActor](), "service-hello2")
         actor.isInstanceOf[RemoteActorRef] should ===(true)
-        actor.path.address should ===(node(slave).address)
+        actor.path.address should ===(node(follower).address)
 
-        val slaveAddress = testConductor.getAddressFor(slave).await
+        val followerAddress = testConductor.getAddressFor(follower).await
         actor ! "identify"
-        expectMsgType[ActorRef].path.address should ===(slaveAddress)
+        expectMsgType[ActorRef].path.address should ===(followerAddress)
       }
 
       enterBarrier("done")
     }
 
     "be able to shutdown system when using remote deployed actor" in within(20 seconds) {
-      runOn(master) {
+      runOn(leader) {
         val actor = system.actorOf(Props[SomeActor](), "service-hello3")
         actor.isInstanceOf[RemoteActorRef] should ===(true)
-        actor.path.address should ===(node(slave).address)
+        actor.path.address should ===(node(follower).address)
         // This watch is in race with the shutdown of the watched system. This race should remain, as the test should
         // handle both cases:
         //  - remote system receives watch, replies with DeathWatchNotification
@@ -126,12 +126,12 @@ abstract class NewRemoteActorSpec(multiNodeConfig: NewRemoteActorMultiJvmSpec)
 
         enterBarrier("deployed")
 
-        // master system is supposed to be shutdown after slave
-        // this should be triggered by slave system.terminate
+        // master system is supposed to be shutdown after follower
+        // this should be triggered by follower system.terminate
         expectMsgPF() { case Terminated(`actor`) => true }
       }
 
-      runOn(slave) {
+      runOn(follower) {
         enterBarrier("deployed")
       }
 
diff --git a/akka-remote-tests/src/multi-jvm/scala/akka/remote/testconductor/TestConductorSpec.scala b/akka-remote-tests/src/multi-jvm/scala/akka/remote/testconductor/TestConductorSpec.scala
index bd3ae7abcc..c8c1cb94f0 100644
--- a/akka-remote-tests/src/multi-jvm/scala/akka/remote/testconductor/TestConductorSpec.scala
+++ b/akka-remote-tests/src/multi-jvm/scala/akka/remote/testconductor/TestConductorSpec.scala
@@ -20,8 +20,8 @@ object TestConductorMultiJvmSpec extends MultiNodeConfig {
       akka.remote.artery.enabled = false 
     """)).withFallback(RemotingMultiNodeSpec.commonConfig))
 
-  val master = role("master")
-  val slave = role("slave")
+  val leader = role("leader")
+  val follower = role("follower")
 
   testTransport(on = true)
 }
@@ -36,14 +36,14 @@ class TestConductorSpec extends RemotingMultiNodeSpec(TestConductorMultiJvmSpec)
   def initialParticipants = 2
 
   lazy val echo = {
-    system.actorSelection(node(master) / "user" / "echo") ! Identify(None)
+    system.actorSelection(node(leader) / "user" / "echo") ! Identify(None)
     expectMsgType[ActorIdentity].ref.get
   }
 
   "A TestConductor" must {
 
     "enter a barrier" taggedAs LongRunningTest in {
-      runOn(master) {
+      runOn(leader) {
         system.actorOf(Props(new Actor {
           def receive = {
             case x => testActor ! x; sender() ! x
@@ -56,20 +56,20 @@ class TestConductorSpec extends RemotingMultiNodeSpec(TestConductorMultiJvmSpec)
 
     "support throttling of network connections" taggedAs LongRunningTest in {
 
-      runOn(slave) {
+      runOn(follower) {
         // start remote network connection so that it can be throttled
         echo ! "start"
       }
 
       expectMsg("start")
 
-      runOn(master) {
-        testConductor.throttle(slave, master, Direction.Send, rateMBit = 0.01).await
+      runOn(leader) {
+        testConductor.throttle(follower, leader, Direction.Send, rateMBit = 0.01).await
       }
 
       enterBarrier("throttled_send")
 
-      runOn(slave) {
+      runOn(follower) {
         for (i <- 0 to 9) echo ! i
       }
 
@@ -80,19 +80,19 @@ class TestConductorSpec extends RemotingMultiNodeSpec(TestConductorMultiJvmSpec)
 
       enterBarrier("throttled_send2")
 
-      runOn(master) {
-        testConductor.throttle(slave, master, Direction.Send, -1).await
-        testConductor.throttle(slave, master, Direction.Receive, rateMBit = 0.01).await
+      runOn(leader) {
+        testConductor.throttle(follower, leader, Direction.Send, -1).await
+        testConductor.throttle(follower, leader, Direction.Receive, rateMBit = 0.01).await
       }
 
       enterBarrier("throttled_recv")
 
-      runOn(slave) {
+      runOn(follower) {
         for (i <- 10 to 19) echo ! i
       }
 
       val (min, max) =
-        if (isNode(master)) (0 seconds, 500 millis)
+        if (isNode(leader)) (0 seconds, 500 millis)
         else (0.3 seconds, 3 seconds)
 
       within(min, max) {
@@ -102,8 +102,8 @@ class TestConductorSpec extends RemotingMultiNodeSpec(TestConductorMultiJvmSpec)
 
       enterBarrier("throttled_recv2")
 
-      runOn(master) {
-        testConductor.throttle(slave, master, Direction.Receive, -1).await
+      runOn(leader) {
+        testConductor.throttle(follower, leader, Direction.Receive, -1).await
       }
 
       enterBarrier("after")