diff --git a/build.xml b/build.xml
index 7bda83c6e..70e50c8cb 100644
--- a/build.xml
+++ b/build.xml
@@ -27,6 +27,7 @@
     <property name="conf.dir" value="${basedir}/src/conf" />
     <property name="lib.dir" value="${basedir}/lib" />
     <property name="tests.dir" value="${basedir}/tests" />
+    <property name="tools.dir" value="${basedir}/tools" />
     
     <property name="server_classes.dir" value="${build.dir}/classes" />
     <property name="webapp_classes.dir" value="${basedir}/src/main/webapp/WEB-INF/classes" />
@@ -257,6 +258,7 @@
     <target name="distclean" depends="clean">
         <delete dir="${build.dir}" />
         <delete dir="${dist.dir}" />
+        <delete dir="${tools.dir}" />
     </target>
 
 </project>
diff --git a/gridworks b/gridworks
index fde70b616..814c25c42 100755
--- a/gridworks
+++ b/gridworks
@@ -219,14 +219,7 @@ findbugs_prepare() {
     FINDBUGS_FILE=`echo $FINDBUGS_URL | sed 's|.*/||'`
     FINDBUGS_DIR="findbugs-1.3.9"
 
-    cd $GRIDWORKS_TOOLS_DIR
-    if [ ! -f "$FINDBUGS_FILE" ] ; then
-        download $FINDBUGS_URL $FINDBUGS_FILE
-    fi
-    if [ ! -d "$FINDBUGS_DIR" ] ; then
-        tar xzf $FINDBUGS_FILE || exit 1
-    fi
-    cd ..
+    tool_download $FINDBUGS_URL $FINDBUGS_FILE $FINDBUGS_DIR
 }
    
 # ----------------------------------------------------------------------------------------------
@@ -289,17 +282,22 @@ mac_dist() {
     get_revision
     
     ANT_PARAMS="-Djarbundler.dir=${GRIDWORKS_TOOLS_DIR}/${JARBUNDLER_DIR}"
-    ant mac
+    ant mac || exit 1
 
     mkdir -p "$GRIDWORKS_BUILD_DIR/mac/.background"
     cp src/graphics/dmg_background/dmg_background.png "$GRIDWORKS_BUILD_DIR/mac/.background/dmg_background.png"
     
     SIZE=30
     
+    if [ -f "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg" ] ; then
+        rm "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg"
+    fi
+    
     TITLE="Gridworks $VERSION"
     echo "Building MacOSX DMG for $TITLE"
-    hdiutil create -srcfolder "$GRIDWORKS_BUILD_DIR/mac" -volname "$TITLE" -fs HFS+ -fsargs "-c c=64,a=16,e=16" -format UDRW -size ${SIZE}m "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg"
-    hdiutil attach -readwrite -noverify -noautoopen "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg"
+    hdiutil create -srcfolder "$GRIDWORKS_BUILD_DIR/mac" -volname "$TITLE" -fs HFS+ -fsargs "-c c=64,a=16,e=16" -format UDRW -size ${SIZE}m "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg" || error "can't create empty DMG"
+    DEVICE=`hdiutil attach -readwrite -noverify -noautoopen "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg" | egrep '^/dev/' | sed 1q | awk '{print $1}'`
+    hdiutil attach "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg"
     
     echo '
        tell application "Finder"
@@ -319,20 +317,30 @@ mac_dist() {
             close
             open               
             update without registering applications
-            delay 2
+            delay 2            
             eject
          end tell
        end tell
-    ' | osascript    
+    ' | osascript || error "error running applescript"
     
     sync
     sync
-    hdiutil convert "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg" -format UDZO -imagekey zlib-level=9 -o "$GRIDWORKS_DIST_DIR/gridworks-$VERSION-$REVISION.dmg"
-    hdiutil internet-enable -yes "$GRIDWORKS_DIST_DIR/gridworks-$VERSION-$REVISION.dmg"
+    hdiutil detach $DEVICE
+    hdiutil convert "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg" -format UDZO -imagekey zlib-level=9 -o "$GRIDWORKS_DIST_DIR/gridworks-$VERSION-$REVISION.dmg" || error "Error compressing DMG"
+    hdiutil internet-enable -yes "$GRIDWORKS_DIST_DIR/gridworks-$VERSION-$REVISION.dmg" || error "Error internet-enabling DMG"
     rm -f "$GRIDWORKS_BUILD_DIR/temp_gridworks.dmg"
 }
 
 test() {
+    ui_test $1 
+    server_test $1
+}
+
+ui_test() {
+    windmill_prepare
+}
+
+server_test() {
     if [ ! -d $GRIDWORKS_TEST_DIR/classes ] ; then
         ant build_tests
         echo ""
@@ -529,6 +537,8 @@ case "$ACTION" in
   clean) ant clean;;
   distclean) ant distclean;;
   test) test $1;;  
+  ui_test) ui_test $1;;  
+  server_test) server_test $1;;  
   findbugs) findbugs;;  
   run) run;;  
   execute) execute $*;;