diff --git a/scheme/filter-window.scm b/scheme/filter-window.scm
index 72d2326..2591cf9 100644
--- a/scheme/filter-window.scm
+++ b/scheme/filter-window.scm
@@ -60,3 +60,62 @@
                #t)
               (else #f))))))
 
+(define (make-subset-window set-viewer method-name set current)
+  (define header-line "Please select")
+  (define header-length (string-length header-line))
+
+  (let* ((set-strings
+          (map display-to-string set))
+         (lines 10)
+         (inner-width
+          (min (apply max header-length
+                      (map string-length set-strings))
+               (COLS)))
+         (dialog (make-app-window (- (quotient (COLS) 2)
+                                     (quotient inner-width 2))
+                                  5
+                                  (+ 4 inner-width)
+                                  lines)))
+    (app-window-init-curses-win! dialog)
+    (let* ((dialog-win (app-window-curses-win dialog))
+           (select-list
+            (make-select-list 
+             (map (lambda (elem elem-str)
+                    (if (member elem current)
+                        (make-marked-text-element 
+                         elem #t elem-str)
+                        (make-unmarked-text-element 
+                         elem #t elem-str)))
+                  set set-strings)
+             (- lines 3))))
+
+      (define (paint)
+        (werase dialog-win)
+        (box dialog-win
+             (ascii->char 0) (ascii->char 0))
+        (mvwaddstr dialog-win 
+                   0
+                   (+ 1 (quotient (- inner-width header-length) 2))
+                   header-line)
+        (paint-selection-list-at select-list 2 1 dialog-win inner-width #t)
+        (wrefresh dialog-win))
+
+      (paint)
+      (lambda (key)
+        (cond ((= key 27)
+               (delete-app-window! dialog)
+               (close-modal-window!)
+               #t)
+              ((select-list-key? key)
+               (set! select-list
+                     (select-list-handle-key-press select-list key))
+               (paint)
+               #f)
+              ((= key 10)
+               (let ((new-set (select-list-get-marked select-list)))
+                 (send set-viewer method-name new-set)
+                 (delete-app-window! dialog)
+                 #t))
+              (else #f))))))
+  
+
diff --git a/scheme/nuit-packages.scm b/scheme/nuit-packages.scm
index 9b9104c..75824e3 100644
--- a/scheme/nuit-packages.scm
+++ b/scheme/nuit-packages.scm
@@ -13,6 +13,7 @@
           write-to-string
           on/off-option-processor
           paste-selection
+          identity-function
 
 	  set-redisplay-everything
 	  unset-redisplay-everything
@@ -418,7 +419,8 @@
 
 (define-interface filter-window-interface
   (export
-   make-filter-window))
+   make-filter-window
+   make-subset-window))
 
 (define-structure filter-window filter-window-interface
   (open scheme
diff --git a/scheme/process.scm b/scheme/process.scm
index b2f6abf..b8c76bf 100644
--- a/scheme/process.scm
+++ b/scheme/process.scm
@@ -2,54 +2,92 @@
   (and (proper-list? thing)
        (every process-info? thing)))
 
-(define (make-header-line)
-  (make-select-line
-   (list
-    (make-unmarked-text-element 'pid #f (right-align-string 6 "PID "))
-    (make-unmarked-text-element 'ppid #f (right-align-string 6 "PPID "))
-    (make-unmarked-text-element 'user #f (left-align-string 9 "USER "))
-    (make-unmarked-text-element '%cpu #f (right-align-string 6 "%CPU "))
-    (make-unmarked-text-element 'command #f "COMMAND"))))
+(define-record-type colops :colops
+  (make-colops < = > select align size to-string header)
+  colops?
+  (< colops-<)
+  (= colops-=)
+  (> colops->)
+  (select colops-select)
+  (align colops-align)
+  (size colops-size)
+  (to-string colops-to-string)
+  (header colops-header))
+
+(define (make-number-colops select align size header)
+  (make-colops < = > select align size number->string header))
+
+(define (make-string-colops select align size header)
+  (make-colops string<? string=? string>?
+               select align size identity-function header))
+
+(define pid-colops
+  (make-number-colops process-info-pid right-align-string 5 "PID"))
+
+(define ppid-colops
+  (make-number-colops process-info-ppid right-align-string 5 "PPID"))
+
+(define user-colops
+  (make-string-colops  process-info-logname
+               left-align-string 8 "USER"))
+
+(define time-colops
+  (make-number-colops process-info-time right-align-string 5 "TIME"))
+
+(define %cpu-colops
+  (make-number-colops process-info-%cpu right-align-string 5 "%CPU"))
+
+(define command-colops ;; actually, we used to display the
+		       ;; command-line here as well
+  (make-string-colops process-info-executable left-align-string 10
+                            "COMMAND"))
 
 
 (define (column->opertions column)
   (case column
-    ((pid) (values < = > process-info-pid))
-    ((ppid) (values < = > process-info-ppid))
-    ((user) (values string<? string=? string>? 
-                    process-info-logname))
-    ((time) (values < = > process-info-time))
-    ((%cpu) (values < = > process-info-%cpu))
-    ((command) (values string<? string=? string>? 
-                       process-info-executable))
+    ((pid) pid-colops)
+    ((ppid) ppid-colops)
+    ((user) user-colops)
+    ((time) time-colops)
+    ((%cpu) %cpu-colops)
+    ((command) command-colops)
     (else
      (error "unknown column" column))))
 
-(define (layout-process width p)
-  (cut-to-size 
+(define (layout-process width p colnames)
+  (cut-to-size
    width
-   (string-append
-    (right-align-string 5 (number->string (process-info-pid p)))
-    " "
-    (right-align-string 5 (number->string (process-info-ppid p)))
-    " "
-    (left-align-string 8 (process-info-logname p))
-    " "
-    (right-align-string 5 (number->string (process-info-%cpu p)))
-    " "
-    (left-align-string 100 (string-append
-                           (process-info-executable p)
-                           " "
-                           (string-join 
-                            (process-info-command-line p)))))))
+   (string-join
+    (map (cut layout-column <> p) 
+         (map column->opertions colnames)))))
+
+(define (layout-column colops p)
+  ((colops-align colops)
+   (colops-size colops)
+   ((colops-to-string colops)
+    ((colops-select colops) p))))
+
+(define (make-header-line colnames)
+  (make-select-line
+   (map
+    (lambda (colname)
+      (let ((colops (column->opertions colname)))
+        (make-unmarked-text-element colname
+                                    #f
+                                    (string-append
+                                     ((colops-align colops)
+                                      (colops-size colops)
+                                      (colops-header colops))
+                                     " "))))
+    colnames)))
 
 (define (make-process-selection-list num-cols num-lines 
-                                     processes)
-  (let ((layout (lambda (p) (layout-process num-cols p))))
+                                     processes colnames)
+  (let ((layout (lambda (p) (layout-process num-cols p colnames))))
     (make-select-list
      (map 
       (lambda (p)
-        (make-unmarked-text-element p #t (layout-process num-cols p)))
+        (make-unmarked-text-element p #t (layout p)))
       processes)
      num-lines)))
 
@@ -58,15 +96,22 @@
 (define-option 'ps 'sort-up-key (char->ascii #\s))
 (define-option 'ps 'sort-down-key (char->ascii #\S))
 (define-option 'ps 'filter-key (char->ascii #\f))
+(define-option 'ps 'columns-key (char->ascii #\c))
+
+(define all-colnames '(pid ppid user time %cpu command))
+(define-option 'ps 'standard-colnames 
+  '(pid ppid user %cpu command))
 
 (define (make-pps-viewer processes buffer)
   (let* ((processes processes)
-         (header-line (make-header-line))
+         (colnames (config 'ps 'standard-colnames))
+         (header-line (make-header-line colnames))
          (select-list
           (make-process-selection-list 
            (result-buffer-num-cols buffer)
            (result-buffer-num-lines buffer)
-           processes)))
+           processes
+           colnames)))
 
     (define (get-selection-as-text self for-scheme-mode? focus-object-table)
       (let* ((marked (select-list-get-marked select-list)))
@@ -98,25 +143,34 @@
            (cond
             ((or (= key (config 'ps 'sort-up-key))
                  (= key (config 'ps 'sort-down-key)))
-             (let ((column (select-line-selected-entry header-line)))
-               (receive (compare-up compare-equal compare-down select)
-                   (column->opertions column)
+             (let* ((column (select-line-selected-entry header-line))
+                    (colops (column->opertions column)))
                  (let ((compare (if (= key (config 'ps 'sort-up-key))
-                                    compare-up
-                                    compare-down)))
+                                    (colops-< colops)
+                                    (colops-> colops)))
+                       (select (colops-select colops)))
+                   
                    (send self 'set-processes!
                          (list-sort
                           (lambda (p1 p2)
                             (compare (select p1) (select p2)))
                           processes))
-                   self))))
+                   self)))
             ((= key (config 'ps 'filter-key))
-             (receive (compare-up compare-equal compare-down select)
-                 (column->opertions 
-                  (select-line-selected-entry header-line))
+             (let ((colops 
+                    (column->opertions 
+                     (select-line-selected-entry header-line))))
                (set-modal-window!
-                (make-filter-window self processes compare-equal select))
+                (make-filter-window self 
+                                    processes
+                                    (colops-= colops)
+                                    (colops-select colops)))
                self))
+            ((= key (config 'ps 'columns-key))
+             (set-modal-window!
+              (make-subset-window self 'set-columns! all-colnames
+                                  colnames))
+             self)
             ((= key (config 'ps 'kill-key))
              (let ((infos
                     (select-list-get-selection select-list)))
@@ -152,7 +206,20 @@
                  (make-process-selection-list 
                   (result-buffer-num-cols buffer)
                   (- (result-buffer-num-lines buffer) 1)
-                  new-processes))))
+                  new-processes
+                  colnames))))
+
+        ((set-columns!)
+         (lambda (self new-colnames)
+           (set! colnames new-colnames)
+           (set! header-line (make-header-line colnames))
+           (set! select-list
+                 (make-process-selection-list 
+                  (result-buffer-num-cols buffer)
+                  (- (result-buffer-num-lines buffer) 1)
+                  processes
+                  colnames))))
+
         (else 
          (error "pps-viewer unknown message" message))))))
 
diff --git a/scheme/utils.scm b/scheme/utils.scm
index 160dbe3..723593a 100644
--- a/scheme/utils.scm
+++ b/scheme/utils.scm
@@ -35,3 +35,5 @@
 
 (define (redisplay-everything?)
   *redisplay-everything*)
+
+(define (identity-function x) x)
\ No newline at end of file