diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index b912c46fe1..ee5f882b7e 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -7,6 +7,14 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 set(CMAKE_Fortran_MODULE_DIRECTORY ${CMAKE_BINARY_DIR}/include)
 
+#===============================================================================
+# Architecture specific definitions
+#===============================================================================
+
+if (${UNIX})
+  add_definitions(-DUNIX)
+endif()
+
 #===============================================================================
 # Command line options
 #===============================================================================
diff --git a/src/plot.F90 b/src/plot.F90
index cedba281c7..9e8348db7f 100644
--- a/src/plot.F90
+++ b/src/plot.F90
@@ -10,6 +10,7 @@ module plot
   use plot_header
   use ppmlib,          only: Image, init_image, allocate_image, &
                              deallocate_image, set_pixel
+  use progress_header, only: ProgressBar
   use string,          only: to_str
 
   implicit none
@@ -109,8 +110,9 @@ contains
     real(8) :: in_pixel
     real(8) :: out_pixel
     real(8) :: xyz(3)
-    type(Image) :: img
-    type(Particle) :: p
+    type(Image)       :: img
+    type(Particle)    :: p
+    type(ProgressBar) :: progress
 
     ! Initialize and allocate space for image
     call init_image(img)
@@ -149,6 +151,7 @@ contains
     p % coord % universe = BASE_UNIVERSE
 
     do y = 1, img % height
+      call progress % set_value(dble(y)/dble(img % height)*100.)
       do x = 1, img % width
 
         ! get pixel color
@@ -228,7 +231,8 @@ contains
     integer :: id           ! id of cell or material
     real(8) :: vox(3)       ! x, y, and z voxel widths
     real(8) :: ll(3)        ! lower left starting point for each sweep direction
-    type(Particle) :: p
+    type(Particle)    :: p
+    type(ProgressBar) :: progress
 
     ! compute voxel widths in each direction
     vox = pl % width/dble(pl % pixels)
@@ -253,6 +257,7 @@ contains
     ll = ll + vox / 2.0
 
     do x = 1, pl % pixels(1)
+      call progress % set_value(dble(x)/dble(pl % pixels(1))*100.)
       do y = 1, pl % pixels(2)
         do z = 1, pl % pixels(3)
 
diff --git a/src/progress_header.F90 b/src/progress_header.F90
new file mode 100644
index 0000000000..d0ee7563a5
--- /dev/null
+++ b/src/progress_header.F90
@@ -0,0 +1,102 @@
+module progress_header
+
+  use, intrinsic :: ISO_FORTRAN_ENV,      only: OUTPUT_UNIT
+
+  implicit none
+
+#ifdef UNIX
+  interface
+    function check_isatty(fd) bind(C, name = 'isatty')
+      use, intrinsic :: ISO_C_BINDING, only: c_int
+      integer(c_int)        :: check_isatty
+      integer(c_int), value :: fd
+    end function check_isatty
+  end interface
+#endif
+
+!===============================================================================
+! PROGRESSBAR
+!===============================================================================
+
+  type ProgressBar
+    private
+    character(len=72) :: bar="???% |                                      " // &
+                             "                           |"
+   contains
+     procedure :: set_value => bar_set_value
+  end type ProgressBar
+
+contains
+ 
+!===============================================================================
+! IS_TERMINAL checks if output is currently being output to a terminal.  Relies
+! on a POSIX implementation of isatty, and defaults to false if that is not
+! available
+!===============================================================================
+
+    function is_terminal() result(istty)
+      logical :: istty
+
+      istty = .true.
+
+#ifdef UNIX
+      if (check_isatty(1) == 0) istty = .false.
+#else
+      istty = .false.
+#endif
+
+    end function is_terminal
+ 
+!===============================================================================
+! BAR_SET_VALUE prints the progress bar without advancing.  The value is
+! specified as percent completion, from 0 to 100.  If the value is ever set to
+! 100 or above, the bar is set to 100 and a newline is written.
+!===============================================================================
+
+  subroutine bar_set_value(self, val)
+
+    class(ProgressBar), intent(inout) :: self
+    real(8),            intent(in)    :: val
+    
+    integer :: i
+
+    if (.not. is_terminal()) return
+
+    ! set the percentage
+    if (val >= 100.) then
+      write(self % bar(1:3), "(I3)") 100
+    else if (val <= 0.) then
+      write(self % bar(1:3), "(I3)") 0
+    else
+      write(self % bar(1:3), "(I3)") int(val)
+    end if
+
+    ! set the bar width
+    if (val >= 100.) then
+      do i=1,65
+        write(self % bar(i+6:i+6), '(A)') '='
+      end do
+    else
+      do i=1,int(dble(65)*val/100.)
+        write(self % bar(i+6:i+6), '(A)') '='
+      end do
+    end if
+
+    write(OUTPUT_UNIT, '(A1,A1,A72)', ADVANCE='no') '+', char(13), self % bar
+    flush(OUTPUT_UNIT)
+    
+    if (val >= 100.) then
+    
+      ! make new line
+      write(OUTPUT_UNIT, "(A)") ""
+      flush(OUTPUT_UNIT)
+      
+      ! reset the bar in case we want to use this instance again
+      self % bar = "???% |                                      " // &
+                   "                           |"
+      
+    end if
+    
+  end subroutine bar_set_value
+
+end module progress_header