diff --git a/lib/README.md b/lib/README.md
index e719821bfc..fd7cba910a 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -1,2 +1,3 @@
-This directory contains standard, low-level C libraries with emphasis on
-being independent and efficient.  They can be used by any port.
+This directory contains third-party, low-level C libraries and SDKs.
+Libraries that do not target any specific platform are generally chosen
+based on them being independent and efficient.
diff --git a/shared/README.md b/shared/README.md
new file mode 100644
index 0000000000..073187b249
--- /dev/null
+++ b/shared/README.md
@@ -0,0 +1,3 @@
+This directory contains libraries, utilities and helper code developed
+specifically for this project.  The code is intended to be portable and
+usable by any port.