Initial revision
diff --git a/Python/fmod.c b/Python/fmod.c
new file mode 100644
index 0000000..58f14f7
--- /dev/null
+++ b/Python/fmod.c
@@ -0,0 +1,27 @@
+/* Portable fmod(x, y) implementation for systems that don't have it */
+
+#include <math.h>
+#include <errno.h>
+
+extern int errno;
+
+double
+fmod(x, y)
+ double x, y;
+{
+ double i, f;
+
+ if (y == 0.0) {
+ errno = EDOM;
+ return 0.0;
+ }
+
+ /* return f such that x = i*y + f for some integer i
+ such that |f| < |y| and f has the same sign as x */
+
+ i = floor(x/y);
+ f = x - i*y;
+ if ((x < 0.0) != (y < 0.0))
+ f = f-y;
+ return f;
+}