diff --git a/proposal/sandbox/dotnet/src/etc/testcases/msbuild.xml b/proposal/sandbox/dotnet/src/etc/testcases/msbuild.xml
new file mode 100644
index 000000000..a9d7f08c2
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/etc/testcases/msbuild.xml
@@ -0,0 +1,21 @@
+<project name="msbuild" basedir="." default="echo"
+  xmlns:dn="antlib:org.apache.tools.ant.taskdefs.optional.dotnet">
+
+  <taskdef 
+    uri="antlib:org.apache.tools.ant.taskdefs.optional.dotnet"
+    resource="org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml">
+    <classpath>
+      <pathelement location="../../../build/lib/dotnet.jar"/>
+    </classpath>
+  </taskdef>
+
+  <target name="echo">
+    <msbuild 
+      buildfile="src/msbuild.proj" 
+      xmlns="antlib:org.apache.tools.ant.taskdefs.optional.dotnet"
+      >
+      <target name="echo"/>
+      <property name="foo" value="bar"/>
+    </msbuild>
+  </target>
+</project>
\ No newline at end of file
diff --git a/proposal/sandbox/dotnet/src/etc/testcases/nant.xml b/proposal/sandbox/dotnet/src/etc/testcases/nant.xml
new file mode 100644
index 000000000..c5ce1f4b7
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/etc/testcases/nant.xml
@@ -0,0 +1,21 @@
+<project name="nant" basedir="." default="echo"
+  xmlns:dn="antlib:org.apache.tools.ant.taskdefs.optional.dotnet">
+
+  <taskdef 
+    uri="antlib:org.apache.tools.ant.taskdefs.optional.dotnet"
+    resource="org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml">
+    <classpath>
+      <pathelement location="../../../build/lib/dotnet.jar"/>
+    </classpath>
+  </taskdef>
+
+  <target name="echo">
+    <nant 
+      buildfile="src/nant.build" 
+      xmlns="antlib:org.apache.tools.ant.taskdefs.optional.dotnet"
+      >
+      <target name="echo"/>
+      <property name="foo" value="bar"/>
+    </nant>
+  </target>
+</project>
\ No newline at end of file
diff --git a/proposal/sandbox/dotnet/src/etc/testcases/src/msbuild.proj b/proposal/sandbox/dotnet/src/etc/testcases/src/msbuild.proj
new file mode 100644
index 000000000..f75233eb2
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/etc/testcases/src/msbuild.proj
@@ -0,0 +1,8 @@
+<Project DefaultTargets="empty">
+
+  <Target Name="empty"/>
+
+  <Target Name="echo">
+    <Task Name="Echo" Message="foo is ${foo}"/>
+  </Target>
+</Project>
diff --git a/proposal/sandbox/dotnet/src/etc/testcases/src/nant.build b/proposal/sandbox/dotnet/src/etc/testcases/src/nant.build
new file mode 100644
index 000000000..8bc3a7a47
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/etc/testcases/src/nant.build
@@ -0,0 +1,8 @@
+<project basedir="." default="empty">
+
+  <target name="empty"/>
+
+  <target name="echo">
+    <echo message="foo is ${foo}"/>
+  </target>
+</project>
diff --git a/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/AbstractBuildTask.java b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/AbstractBuildTask.java
new file mode 100644
index 000000000..a3fa5d91a
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/AbstractBuildTask.java
@@ -0,0 +1,205 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "Ant" and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+package org.apache.tools.ant.taskdefs.optional.dotnet;
+
+import org.apache.tools.ant.Task;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Base class for NAntTask and MSBuildTask.
+ */
+public abstract class AbstractBuildTask extends Task {
+
+    /**
+     * The buildfile to invoke the build tool for.
+     */
+    private File buildFile;
+
+    /**
+     * The targets to execute.
+     */
+    private List targets = new ArrayList();
+
+    /**
+     * Properties to set.
+     */
+    private List properties = new ArrayList(1);
+
+    /**
+     * Empty constructor.
+     */
+    protected AbstractBuildTask() {
+    }
+
+    /**
+     * Sets the name of the build file.
+     */
+    public final void setBuildfile(File f) {
+        buildFile = f;
+    }
+
+    /**
+     * A target.
+     */
+    public static class Target {
+        private String name;
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+    }
+
+    /**
+     * A target to execute.
+     */
+    public final void addTarget(Target t) {
+        targets.add(t);
+    }
+
+    /**
+     * A property.
+     */
+    // XXX, could have reused Property or Environment.Variable 
+    //      - not decided so far
+    public static class Property {
+        private String name;
+        private String value;
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+
+        public String getValue() {
+            return value;
+        }
+    }
+
+    /**
+     * A target to execute.
+     */
+    public final void addProperty(Property t) {
+        properties.add(t);
+    }
+
+    /**
+     * Must return the executable.
+     *
+     * @return must not return null
+     */
+    protected abstract String getExecutable();
+
+    /**
+     * Must return buildfile argument(s).
+     *
+     * @param buildFile the absolute File for the buildfile or null if
+     * the user didn't specify a buildfile.
+     *
+     * @return must not return null
+     */
+    protected abstract String[] getBuildfileArguments(File buildFile);
+
+    /**
+     * Must return target argument(s).
+     *
+     * @return must not return null
+     */
+    protected abstract String[] getTargetArguments(List targets);
+
+    /**
+     * Must return property argument(s).
+     *
+     * @return must not return null
+     */
+    protected abstract String[] getPropertyArguments(List properties);
+
+    /**
+     * Perform the build.
+     */
+    public void execute() {
+        DotNetExecTask exec = new DotNetExecTask();
+        exec.setProject(getProject());
+        exec.setExecutable(getExecutable());
+        exec.setTaskName(getTaskName());
+        String[] args = getPropertyArguments(properties);
+        for (int i = 0; i < args.length; i++) {
+            exec.createArg().setValue(args[i]);
+        }
+        args = getTargetArguments(targets);
+        for (int i = 0; i < args.length; i++) {
+            exec.createArg().setValue(args[i]);
+        }
+        args = getBuildfileArguments(buildFile);
+        for (int i = 0; i < args.length; i++) {
+            exec.createArg().setValue(args[i]);
+        }
+        exec.execute();
+    }
+}
diff --git a/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/MSBuildTask.java b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/MSBuildTask.java
new file mode 100644
index 000000000..f830ec2d1
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/MSBuildTask.java
@@ -0,0 +1,122 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "Ant" and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+package org.apache.tools.ant.taskdefs.optional.dotnet;
+
+import java.io.File;
+import java.util.Iterator;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Runs a MSBuild build process.
+ */
+public class MSBuildTask extends AbstractBuildTask {
+
+    public MSBuildTask() {
+        super();
+    }
+
+    protected String getExecutable() {
+        return "MSBuild.exe";
+    }
+
+    protected String[] getBuildfileArguments(File buildFile) {
+        if (buildFile != null) {
+            return new String[] {
+                buildFile.getAbsolutePath()
+            };
+        } else {
+            return new String[0];
+        }
+    }
+
+    protected String[] getTargetArguments(List targets) {
+        if (targets.size() > 0) {
+            StringBuffer sb = new StringBuffer("/targets:");
+            Iterator iter = targets.iterator();
+            boolean first = true;
+            while (iter.hasNext()) {
+                AbstractBuildTask.Target t = 
+                    (AbstractBuildTask.Target) iter.next();
+                if (!first) {
+                    sb.append(";");
+                }
+                sb.append(t.getName());
+            }
+            return new String[]{sb.toString()};
+        } else {
+            return new String[0];
+        }
+    }
+
+    protected String[] getPropertyArguments(List properties) {
+        if (properties.size() > 0) {
+            StringBuffer sb = new StringBuffer("/property:");
+            Iterator iter = properties.iterator();
+            boolean first = true;
+            while (iter.hasNext()) {
+                AbstractBuildTask.Property p = 
+                    (AbstractBuildTask.Property) iter.next();
+                if (!first) {
+                    sb.append(";");
+                }
+                sb.append(p.getName()).append("=").append(p.getValue());
+            }
+            return new String[]{sb.toString()};
+        } else {
+            return new String[0];
+        }
+    }
+}
diff --git a/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/NAntTask.java b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/NAntTask.java
new file mode 100644
index 000000000..bd228e9fa
--- /dev/null
+++ b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/NAntTask.java
@@ -0,0 +1,105 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "Ant" and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+package org.apache.tools.ant.taskdefs.optional.dotnet;
+
+import java.io.File;
+import java.util.Iterator;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Runs a NAnt build process.
+ */
+public class NAntTask extends AbstractBuildTask {
+
+    public NAntTask() {
+        super();
+    }
+
+    protected String getExecutable() {
+        return "NAnt.exe";
+    }
+
+    protected String[] getBuildfileArguments(File buildFile) {
+        if (buildFile != null) {
+            return new String[] {
+                "-buildfile:" + buildFile.getAbsolutePath()
+            };
+        } else {
+            return new String[0];
+        }
+    }
+
+    protected String[] getTargetArguments(List targets) {
+        ArrayList al = new ArrayList(targets.size());
+        Iterator iter = targets.iterator();
+        while (iter.hasNext()) {
+            AbstractBuildTask.Target t = (AbstractBuildTask.Target) iter.next();
+            al.add(t.getName());
+        }
+        return (String[]) al.toArray(new String[al.size()]);
+    }
+
+    protected String[] getPropertyArguments(List properties) {
+        ArrayList al = new ArrayList(properties.size());
+        Iterator iter = properties.iterator();
+        while (iter.hasNext()) {
+            AbstractBuildTask.Property p = 
+                (AbstractBuildTask.Property) iter.next();
+            al.add("-D:" + p.getName() + "=" + p.getValue());
+        }
+        return (String[]) al.toArray(new String[al.size()]);
+    }
+}
diff --git a/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml
index 80260cdc4..ade2099b1 100644
--- a/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml
+++ b/proposal/sandbox/dotnet/src/main/org/apache/tools/ant/taskdefs/optional/dotnet/antlib.xml
@@ -3,4 +3,12 @@
     name="dotnetexec"
     classname="org.apache.tools.ant.taskdefs.optional.dotnet.DotNetExecTask"
     />
+  <taskdef
+    name="msbuild"
+    classname="org.apache.tools.ant.taskdefs.optional.dotnet.MSBuildTask"
+    />
+  <taskdef
+    name="nant"
+    classname="org.apache.tools.ant.taskdefs.optional.dotnet.NAntTask"
+    />
 </antlib>