diff --git a/HACKING b/HACKING
new file mode 100644
index 00000000..cd6cfb59
--- /dev/null
+++ b/HACKING
@@ -0,0 +1,54 @@
+* HACKING
+
+Here are some short guidelines for hacking on the 'mu' source code.
+
+** Coding style
+
+   For consistency and even more important, to keep things understandable, mu
+   follows the following rules:
+
+   1. basic code layout is like in the Linux kernel coding style, with the '{'
+      on the same line as the statement, except for functions. Tabs/spaces
+      have width 8.
+
+   2. lines must not exceed 80 characters
+
+   3. functions must not exceed 30 lines (there may be rare exceptions), and
+      30 lines is already pretty long.
+
+   4. source files should not exceed 1000 lines
+
+   5. a function's cyclomatic complexity should not exceed 10 (there may be
+      rare exceptions). You can test the cyclomatic complexity with the
+      pmccabe tool
+
+   6. filenames have their components separated with dashes (e.g, 'mu-log.h')
+
+   7. global functions have the prefix based on their module, e.g., mu-foo.h
+      declares a function of 'mu_foo_bar (int a);', mu-foo.c implements this.
+
+   8. non-global functions *don't* have the module prefix, and are declared
+      static.
+
+   9. functions have their return type on a separate line before the function
+      name
+
+   10. in C code, variable-declarations are at the beginning of a block; in
+       principle, C++ follows that same guideline, unless for heavy yet
+       uncertain initializations following RAII.
+
+   11. returned strings of type char* must be freed by the caller; if they are
+       not to be freed, 'const char*' should be used instead
+
+
+
+
+
+
+
+
+
+
+#+ Local Variables: ***
+#+ mode:org ***
+#+ End: ***