diff --git a/common/src/main/java/org/implab/gradle/common/ProjectMixin.java b/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
--- a/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
+++ b/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
@@ -9,6 +9,8 @@ import org.gradle.api.Project;
 import org.gradle.api.Task;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.file.Directory;
+import org.gradle.api.tasks.TaskContainer;
+import org.implab.gradle.common.dsl.TaskGroup;
 import org.implab.gradle.common.dsl.TaskSpec;
 import org.implab.gradle.common.dsl.TasksMixin;
 import org.implab.gradle.common.utils.ExtraProps;
@@ -24,6 +26,16 @@ public interface ProjectMixin extends Ta
         return new TaskSpec<>(provider);
     }
 
+    /** Creates a new task group */
+    default TaskGroup taskGroup(String name) {
+        return new TaskGroup(name) {
+            @Override
+            protected TaskContainer tasks() {
+                return getProject().getTasks();
+            }
+        };
+    }
+
     /** Registers the new configuration */
     default NamedDomainObjectProvider<Configuration> configuration(String name, Action<? super Configuration> configure) {
         return getProject().getConfigurations().register(name, configure);
diff --git a/common/src/main/java/org/implab/gradle/common/exec/ProcessSpec.java b/common/src/main/java/org/implab/gradle/common/dsl/ProcessSpec.java
rename from common/src/main/java/org/implab/gradle/common/exec/ProcessSpec.java
rename to common/src/main/java/org/implab/gradle/common/dsl/ProcessSpec.java
--- a/common/src/main/java/org/implab/gradle/common/exec/ProcessSpec.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/ProcessSpec.java
@@ -1,17 +1,15 @@
-package org.implab.gradle.common.exec;
+package org.implab.gradle.common.dsl;
 
 import java.io.File;
-import java.io.IOException;
-import java.lang.ProcessBuilder.Redirect;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
+
+import org.implab.gradle.common.exec.Executor;
+import org.implab.gradle.common.exec.RedirectFrom;
+import org.implab.gradle.common.exec.RedirectTo;
 
 public class ProcessSpec {
-    private final ProcessBuilder builder;
-
     private RedirectFrom inputRedirect;
 
     private RedirectTo outputRedirect;
@@ -22,51 +20,6 @@ public class ProcessSpec {
 
     private File directory;
 
-    public ProcessSpec() {
-        builder = new ProcessBuilder();
-    }
-
-    public CompletableFuture<Integer> start() throws IOException {
-        var tasks = new ArrayList<CompletableFuture<?>>();
-
-        builder.command(command);
-        builder.directory(directory);
-
-        // discard stdout if not redirected
-        if (outputRedirect == null)
-            builder.redirectOutput(Redirect.DISCARD);
-
-        // discard stderr if not redirected
-        if (errorRedirect == null)
-            builder.redirectError(Redirect.DISCARD);
-
-        // run process
-        var proc = builder.start();
-
-        tasks.add(proc.onExit());
-
-        if (inputRedirect != null)
-            tasks.add(inputRedirect.redirect(proc.getOutputStream()));
-
-        if (outputRedirect != null)
-            tasks.add(outputRedirect.redirect(proc.getInputStream()));
-
-        if (errorRedirect != null)
-            tasks.add(errorRedirect.redirect(proc.getErrorStream()));
-
-        return CompletableFuture
-                .allOf(tasks.toArray(new CompletableFuture<?>[0]))
-                .thenApply(t -> proc.exitValue());
-    }
-
-    public Integer exec() throws InterruptedException, ExecutionException, IOException {
-        return start().get();
-    }
-
-    public List<String> command() {
-        return command;
-    }
-
     public ProcessSpec command(String... args) {
         command = new ArrayList<>();
         args(args);
@@ -109,4 +62,17 @@ public class ProcessSpec {
         outputRedirect = to;
         return this;
     }
+
+    public void accept(Executor executor) {
+        command.forEach(executor::argument);
+        executor.directory(directory);
+        if (inputRedirect != null)
+            executor.stdin(inputRedirect);
+        if (outputRedirect != null)
+            executor.stdout(outputRedirect);
+        if (errorRedirect != null)
+            executor.stderr(errorRedirect);
+    }
+
+
 }
diff --git a/common/src/main/java/org/implab/gradle/common/dsl/TaskReference.java b/common/src/main/java/org/implab/gradle/common/dsl/TaskDependency.java
rename from common/src/main/java/org/implab/gradle/common/dsl/TaskReference.java
rename to common/src/main/java/org/implab/gradle/common/dsl/TaskDependency.java
--- a/common/src/main/java/org/implab/gradle/common/dsl/TaskReference.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/TaskDependency.java
@@ -3,19 +3,19 @@ package org.implab.gradle.common.dsl;
 import org.gradle.api.Buildable;
 import org.gradle.api.tasks.TaskProvider;
 
-public interface TaskReference {
+public interface TaskDependency {
 
     Object reference();
 
-    public static TaskReference named(String name) {
+    public static TaskDependency named(String name) {
         return () -> name;
     }
 
-    public static TaskReference provider(TaskProvider<?> provider) {
+    public static TaskDependency provider(TaskProvider<?> provider) {
         return () -> provider;
     }
 
-    public static TaskReference buildable(Buildable dependency) {
+    public static TaskDependency buildable(Buildable dependency) {
         return () -> dependency;
     }
 
diff --git a/common/src/main/java/org/implab/gradle/common/dsl/TaskSpec.java b/common/src/main/java/org/implab/gradle/common/dsl/TaskSpec.java
--- a/common/src/main/java/org/implab/gradle/common/dsl/TaskSpec.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/TaskSpec.java
@@ -6,7 +6,10 @@ import org.gradle.api.Action;
 import org.gradle.api.Task;
 import org.gradle.api.tasks.TaskProvider;
 
-public class TaskSpec<T extends Task> implements TaskReference {
+/**
+ * Wrapper around TaskProvider for simplified lazy task configuration
+ */
+public class TaskSpec<T extends Task> implements TaskDependency {
     private final TaskProvider<T> taskProvider;
 
     public TaskSpec(TaskProvider<T> taskProvider) {
@@ -18,17 +21,17 @@ public class TaskSpec<T extends Task> im
         return this;
     }
 
-    public TaskSpec<T> dependsOn(TaskReference... other) {
+    public TaskSpec<T> dependsOn(TaskDependency... other) {
         taskProvider.configure(t -> t.dependsOn(references(other)));
         return this;
     }
 
-    public TaskSpec<T> finalizedBy(TaskReference... other) {
+    public TaskSpec<T> finalizedBy(TaskDependency... other) {
         taskProvider.configure(t -> t.finalizedBy(references(other)));
         return this;
     }
 
-    public TaskSpec<T> mustRunAfter(TaskReference... other) {
+    public TaskSpec<T> mustRunAfter(TaskDependency... other) {
         taskProvider.configure(t -> t.mustRunAfter(references(other)));
         return this;
     }
@@ -43,12 +46,13 @@ public class TaskSpec<T extends Task> im
         return this;
     }
 
+    /** Returns a task provider for this task, can be used as dependency object */
     @Override
     public Object reference() {
         return taskProvider;
     }
 
-    private static Object[] references(TaskReference[] other) {
-        return Stream.of(other).map(TaskReference::reference).toArray(Object[]::new);
+    private static Object[] references(TaskDependency[] other) {
+        return Stream.of(other).map(TaskDependency::reference).toArray(Object[]::new);
     }
 }