diff --git a/src/.gitignore b/src/.gitignore
new file mode 100644
index 0000000..37a9bfd
--- /dev/null
+++ b/src/.gitignore
@@ -0,0 +1,3 @@
+*.o
+*.c
+*.h
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..aeea3d7
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1,11 @@
+CC=gcc
+CFLAGS=
+
+SOURCE_FILES=$(wildcard *.org)
+
+%.o: %.c.org
+	- emacs --quick --no-init-file --batch --eval "(require 'org)" --eval '(org-babel-tangle-file "$^")'
+	- $(CC) $(CFLAGS) -c $*.c -o $@
+	- rm -f $*.c $*.h
+
+
diff --git a/src/README.org b/src/README.org
new file mode 100644
index 0000000..49abb06
--- /dev/null
+++ b/src/README.org
@@ -0,0 +1,12 @@
+Source files are written in org-mode format, to provide useful comments and
+LaTex formulas around the code.
+
+The code is extracted from the org files using Emacs in the `Makefile`, and
+then he produced files are compiled.
+
+For a better experience, editing can be done with Emacs. Note that Emacs can
+behave like Vim when switched into ``Evil'' mode.
+
+
+
+
diff --git a/src/qmckl_context.c.org b/src/qmckl_context.c.org
new file mode 100644
index 0000000..c21cfd4
--- /dev/null
+++ b/src/qmckl_context.c.org
@@ -0,0 +1,126 @@
+# -*- mode: org -*-
+
+#+BEGIN_SRC C :tangle qmckl_context.c
+#include <stdlib.h>   /* malloc */
+#include "qmckl_context.h"
+#+END_SRC
+
+* Context
+  
+  The context variable is a handle for the state of the library, and
+  is stored in the following data structure, which can't be seen
+  outside of the library.
+
+  #+BEGIN_SRC C :tangle qmckl_context.h
+#define QMCKL_DEFAULT_PRECISION 53
+#define QMCKL_DEFAULT_RANGE     2
+
+typedef long int qmckl_context ;
+  #+END_SRC
+
+
+  #+BEGIN_SRC C :tangle qmckl_context.c
+typedef struct qmckl_context_struct_ {
+  struct qmckl_context_struct_ * prev;
+  int precision;  
+  int range;  
+} qmckl_context_struct;
+  #+END_SRC
+
+  To create a new context, use =qmckl_context_create()=. If the creation
+  failed, the function returns 0. On success, a pointer to a context
+  is returned as a long integer.
+
+  #+BEGIN_SRC C :tangle qmckl_context.h
+qmckl_context qmckl_context_create();
+  #+END_SRC
+
+  #+BEGIN_SRC C :tangle qmckl_context.c
+qmckl_context qmckl_context_create() {
+
+  qmckl_context_struct*  context;
+
+  context = (qmckl_context_struct*) malloc (sizeof(qmckl_context_struct));
+  if (context == NULL) {
+    return (qmckl_context) 0;
+  }
+
+  context->prev      = NULL;
+  context->precision = QMCKL_DEFAULT_PRECISION;
+  context->range     = QMCKL_DEFAULT_RANGE;
+
+  return (qmckl_context) context;
+}
+  #+END_SRC
+  
+
+  #+BEGIN_SRC C :tangle qmckl_context.h
+qmckl_context qmckl_context_copy(qmckl_context context);
+  #+END_SRC
+
+  #+BEGIN_SRC C :tangle qmckl_context.c
+qmckl_context qmckl_context_copy(qmckl_context context) {
+
+  qmckl_context_struct* old_context;
+  qmckl_context_struct* new_context;
+
+  new_context = (qmckl_context_struct*) malloc (sizeof(qmckl_context_struct));
+  if (new_context == NULL) {
+    return (qmckl_context) 0;
+  }
+
+  old_context = (qmckl_context_struct*) context;
+
+  new_context->prev      = old_context;
+  new_context->precision = old_context->precision; 
+  new_context->range     = old_context->range;
+
+  return (qmckl_context) new_context;
+}
+  #+END_SRC
+  
+
+* Precision
+
+  The following functions set the expected required precision and range.
+  =precision= should be an integer between 2 and 53, and =range= should be
+  an integer between 2 and 11.
+  These functions return 0 upon success.
+
+  #+BEGIN_SRC C :tangle qmckl_context.h
+qmckl_context qmckl_context_set_precision(qmckl_context context, int precision);
+  #+END_SRC
+
+  #+BEGIN_SRC C :tangle qmckl_context.c
+qmckl_context qmckl_context_set_precision(qmckl_context context, int precision) {
+  qmckl_context_struct* ctx;
+
+  if (precision <  2) return (qmckl_context) 0;
+  if (precision > 53) return (qmckl_context) 0;
+
+  ctx = (qmckl_context_struct*) qmckl_context_copy(context);
+  ctx->precision = precision;
+  return (qmckl_context) ctx;
+}
+  #+END_SRC
+
+
+  #+BEGIN_SRC C :tangle qmckl_context.h
+qmckl_context qmckl_context_set_range(qmckl_context context, int range);
+  #+END_SRC
+
+  #+BEGIN_SRC C :tangle qmckl_context.c
+qmckl_context qmckl_context_set_range(qmckl_context context, int range) {
+  qmckl_context_struct* ctx;
+
+  if (range <  2) return (qmckl_context) 0;
+  if (range > 11) return (qmckl_context) 0;
+
+  ctx = (qmckl_context_struct*) qmckl_context_copy(context);
+  ctx->range = range;
+  return (qmckl_context) ctx;
+}
+  #+END_SRC
+
+
+