GILLES Sebastien
--- a/6-InRealEnvironment/1-SetUpEnvironment.ipynb
+++ b/6-InRealEnvironment/1-SetUpEnvironment.ipynb
    "\n",
    "This will install _Apple Clang_ which is a customized version of `clang`. Unfortunately, Apple stopped providing the version of mainstream clang it is built upon; it's therefore more difficult to check if a new standard feature is already supported or not.\n",
    "\n",
-    "It is also possible to install gcc on macOS; I personally use the tarballs provided by [this site](http://hpc.sourceforge.net/).\n"
+    "It is also possible to install gcc on macOS; I personally use [Homebrew](https://brew.sh) to do so.\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## STL\n",
+    "\n",
+    "Besides the compiler, you may also choose which implementation of the STL you want to use. There are two mainstream choices:\n",
+    "\n",
+    "- `libstdc++`, which is the STL provided along gcc by GNU. This is the default choice for many Linux distro, ahd there is fat chance the binaries, libraries and share libraries in your package system was compiled with this one.\n",