diff --git a/src/ikarus.boot b/src/ikarus.boot
index 9fa4972..0dab6ce 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.strings.ss b/src/ikarus.strings.ss
index 0b65e8b..442bb92 100644
--- a/src/ikarus.strings.ss
+++ b/src/ikarus.strings.ss
@@ -1,8 +1,9 @@
 
 (library (ikarus strings)
-  (export string-length string-ref string-set! make-string string->list string=?
+  (export string-length string-ref string-set! make-string string->list
           string-append substring string list->string uuid
-          string-copy string-for-each string-fill!)
+          string-copy string-for-each string-fill! 
+          string=? string<? string<=? string>? string>=?)
   (import 
     (ikarus system $strings)
     (ikarus system $fx)
@@ -10,8 +11,9 @@
     (ikarus system $bytevectors)
     (ikarus system $pairs)
     (except (ikarus) string-length string-ref string-set! make-string
-            string->list string=? string-append substring string
+            string->list string-append substring string
             list->string uuid string-copy string-for-each
+            string=? string<? string<=? string>? string>=?
             string-fill!))
 
 
@@ -165,6 +167,97 @@
              (strings=? s s* ($string-length s))
              (err s))])))
 
+
+  (define string-cmp
+    (lambda (who cmp)
+      (case-lambda
+        [(s1 s2) 
+         (if (string? s1)
+             (if (string? s2) 
+                 (cmp s1 s2)
+                 (error who "~s is not a string" s2))
+             (error who "~s is not a string" s1))]
+        [(s1 . s*) 
+         (if (string? s1) 
+             (let f ([s1 s1] [s* s*]) 
+               (cond
+                 [(null? s*) #t]
+                 [else
+                  (let ([s2 (car s*)])
+                    (if (string? s2) 
+                        (if (cmp s1 s2) 
+                            (f s2 (cdr s*))
+                            (let f ([s* (cdr s*)])
+                              (cond
+                                [(null? s*) #f]
+                                [(string? (car s*)) 
+                                 (f (cdr s*))]
+                                [else 
+                                 (error who "~s is not a string" 
+                                   (car s*))]))))
+                        (error who "~s is not a string" s2))])))
+             (error who "~s is not a string" s1)])))
+  
+  (define ($string<? s1 s2)
+    (let ([n1 ($string-length s1)]
+          [n2 ($string-length s2)])
+      (if ($fx< n1 n2)
+          (let f ([i 0] [n n1] [s1 s1] [s2 s2])
+            (if ($fx= i n)
+                #t
+                (let ([c1 ($string-ref s1 i)]
+                      [c2 ($string-ref s2 i)])
+                  (if ($char< c1 c2) 
+                      #t
+                      (if ($char= c1 c2) 
+                          (f ($fxadd1 i) n s1 s2)
+                          #f)))))
+          (let f ([i 0] [n n2] [s1 s1] [s2 s2])
+            (if ($fx= i n)
+                #f
+                (let ([c1 ($string-ref s1 i)]
+                      [c2 ($string-ref s2 i)])
+                  (if ($char< c1 c2) 
+                      #t
+                      (if ($char= c1 c2) 
+                          (f ($fxadd1 i) n s1 s2)
+                          #f))))))))
+
+
+  (define ($string<=? s1 s2)
+    (let ([n1 ($string-length s1)]
+          [n2 ($string-length s2)])
+      (if ($fx<= n1 n2)
+          (let f ([i 0] [n n1] [s1 s1] [s2 s2])
+            (if ($fx= i n)
+                #t
+                (let ([c1 ($string-ref s1 i)]
+                      [c2 ($string-ref s2 i)])
+                  (if ($char< c1 c2)
+                      #t
+                      (if ($char= c1 c2) 
+                          (f ($fxadd1 i) n s1 s2)
+                          #f)))))
+          (let f ([i 0] [n n2] [s1 s1] [s2 s2])
+            (if ($fx= i n)
+                #f
+                (let ([c1 ($string-ref s1 i)]
+                      [c2 ($string-ref s2 i)])
+                  (if ($char< c1 c2) 
+                      #t
+                      (if ($char= c1 c2) 
+                          (f ($fxadd1 i) n s1 s2)
+                          #f))))))))
+  (define ($string>? s1 s2) 
+    ($string<? s2 s1))
+  (define ($string>=? s1 s2) 
+    ($string<=? s2 s1))
+
+  (define string<? (string-cmp 'string<? $string<?))
+  (define string<=? (string-cmp 'string<=? $string<=?))
+  (define string>? (string-cmp 'string>? $string>?))
+  (define string>=? (string-cmp 'string>=? $string>=?))
+
   (define string->list
     (lambda (x)
       (unless (string? x)
diff --git a/src/ikarus.unicode-data.ss b/src/ikarus.unicode-data.ss
index 8dd3b7a..61863d4 100644
--- a/src/ikarus.unicode-data.ss
+++ b/src/ikarus.unicode-data.ss
@@ -3,8 +3,8 @@
   (export unicode-printable-char?
           char-downcase char-upcase char-titlecase char-foldcase
           char-ci=? char-ci<? char-ci<=? char-ci>? char-ci>=?
-          string-foldcase
-          string-ci=?)
+          string-ci=?  string-ci<?  string-ci<=?  string-ci>?  string-ci>=?
+          string-foldcase)
   (import 
     (ikarus system $fx)
     (ikarus system $vectors)
@@ -14,8 +14,8 @@
     (ikarus system $io)
     (except (ikarus) char-downcase char-upcase char-titlecase char-foldcase
             char-ci=? char-ci<? char-ci<=? char-ci>? char-ci>=?
-            string-foldcase
-            string-ci=?))
+            string-ci=?  string-ci<?  string-ci<=?  string-ci>?  string-ci>=?
+            string-foldcase))
 
   (include "unicode/unicode-constituents.ss")
   (include "unicode/unicode-char-cases.ss")
@@ -160,12 +160,52 @@
         ($string-foldcase str)
         (error 'string-foldcase "~s is not a string" str)))
 
-  (define (string-ci=? s1 s2)
-    (if (string? s1)
-        (if (string? s2) 
-            (string=? ($string-foldcase s1) ($string-foldcase s2))
-            (error 'string-ci=? "~s is not a string" s2))
-        (error 'string-ci=? "~s is not a string" s1)))
+  (define string-ci-cmp
+    (lambda (who cmp)
+      (case-lambda
+        [(s1 s2) 
+         (if (string? s1)
+             (if (string? s2) 
+                 (cmp ($string-foldcase s1) ($string-foldcase s2))
+                 (error who "~s is not a string" s2))
+             (error who "~s is not a string" s1))]
+        [(s1 . s*) 
+         (if (string? s1) 
+             (let ([s1 ($string-foldcase s1)])
+               (let f ([s1 s1] [s* s*]) 
+                 (cond
+                   [(null? s*) #t]
+                   [else
+                    (let ([s2 (car s*)])
+                      (if (string? s2) 
+                          (let ([s2 ($string-foldcase s2)])
+                            (if (cmp s1 s2) 
+                                (f s2 (cdr s*))
+                                (let f ([s* (cdr s*)])
+                                  (cond
+                                    [(null? s*) #f]
+                                    [(string? (car s*)) 
+                                     (f (cdr s*))]
+                                    [else 
+                                     (error who "~s is not a string" 
+                                       (car s*))]))))
+                          (error who "~s is not a string" s2)))])))
+             (error who "~s is not a string" s1))])))
+
+
+  (define string-ci=?  (string-ci-cmp 'string-ci=? string=?))
+  (define string-ci<?  (string-ci-cmp 'string-ci<? string<?))
+  (define string-ci<=? (string-ci-cmp 'string-ci<=? string<=?))
+  (define string-ci>?  (string-ci-cmp 'string-ci>? string>?))
+  (define string-ci>=? (string-ci-cmp 'string-ci>=? string>=?))
+
+
+  ;(define (string-ci=? s1 s2)
+  ;  (if (string? s1)
+  ;      (if (string? s2) 
+  ;          (string=? ($string-foldcase s1) ($string-foldcase s2))
+  ;          (error 'string-ci=? "~s is not a string" s2))
+  ;      (error 'string-ci=? "~s is not a string" s1)))
 
 
   )
diff --git a/src/makefile.ss b/src/makefile.ss
index 2aa2d6c..27cc54e 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -352,7 +352,15 @@
     [string-fill!            i r]
     [string-length           i r]
     [string=?                i r]
+    [string<?                i r]
+    [string<=?                i r]
+    [string>?                i r]
+    [string>=?                i r]
     [string-ci=?             i unicode]
+    [string-ci<?             i unicode]
+    [string-ci<=?             i unicode]
+    [string-ci>?             i unicode]
+    [string-ci>=?             i unicode]
     [substring               i r]
     [string-copy             i r]
     [string-append           i r]
diff --git a/src/run-tests.ss b/src/run-tests.ss
index e7df122..59e59c3 100755
--- a/src/run-tests.ss
+++ b/src/run-tests.ss
@@ -3,6 +3,7 @@
 (import (ikarus)
         (tests reader)
         (tests bytevectors)
+        (tests strings)
         (tests bignum-to-flonum)
         (tests string-to-number))
 
@@ -21,6 +22,7 @@
 
 (test-reader)
 (test-bytevectors)
+(test-strings)
 (test-exact-integer-sqrt)
 (test-bignum-to-flonum)
 (test-string-to-number)
diff --git a/src/tests/strings.ss b/src/tests/strings.ss
new file mode 100644
index 0000000..c0f00d5
--- /dev/null
+++ b/src/tests/strings.ss
@@ -0,0 +1,20 @@
+(library (tests strings)
+  (export test-strings)
+  (import (ikarus) (tests framework))
+
+  (define-tests test-strings
+    [values
+     (string-ci=? "Strasse" "Stra\xDF;e")]
+    ;[(lambda (x) (string=? x "STRASSE"))
+    ; (string-upcase "Stra\xDF;e")]
+    ;[(lambda (x) (string=? x "stra\xDF;e"))
+    ; (string-downcase "Stra\xDF;e")]
+    [(lambda (x) (string=? x "strasse")) 
+     (string-foldcase "Stra\xDF;e")]
+    ;[(lambda (x) (string=? x "strasse")) 
+    ; (string-downcase "STRASSE")]
+    [values (string-ci=? "Stra\xDF;e" "Strasse")]
+    [values (string-ci=? "Stra\xDF;e" "STRASSE")]
+    ))
+
+
diff --git a/src/todo-r6rs.ss b/src/todo-r6rs.ss
index 8804bc1..b1b5235 100755
--- a/src/todo-r6rs.ss
+++ b/src/todo-r6rs.ss
@@ -753,11 +753,11 @@
     [char-title-case?                           S uc]
     [char-upper-case?                           S uc se]
     [char-whitespace?                           C uc se]
-    [string-ci<=?                               S uc se]
-    [string-ci<?                                S uc se]
-    [string-ci=?                                S uc se]
-    [string-ci>=?                               S uc se]
-    [string-ci>?                                S uc se]
+    [string-ci<=?                               C uc se]
+    [string-ci<?                                C uc se]
+    [string-ci=?                                C uc se]
+    [string-ci>=?                               C uc se]
+    [string-ci>?                                C uc se]
     [string-downcase                            S uc]
     [string-foldcase                            S uc]
     [string-normalize-nfc                       S uc]