diff --git a/README.md b/README.md
index 4ded609..fb71833 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,45 @@ This is the repo for build, test and deploy scripts for the [GNU Compiler Collec
 
 # Versions
 
-Versions built are :
+We build the latest stable version of each major release of the compiler chain :
 
-  1. 4.9.2
-  1. 5.1.0
-  1. 5.2.0
-  1. 5.3.0
+## Current versions :
+
+  1. 4.9.4
   1. 5.4.0
-  1. 6.1.0
+  2. 6.3.0
+
+## Old versions
+
+There are also a few old modules from previous releases. YMMV.
+
+1. ~~4.9.2~~
+1. ~~5.1.0~~
+1. ~~5.2.0~~
+1. ~~5.3.0~~
+1. ~~6.1.0~~
+
+Version 7.x is not built yet, due to support for java being removed.
+
+
+# Downstream products
+
+Almost all CODE-RADE applications in research domains (astronomy, biology, chemistry, _etc_) are built with one or more of these compilers. As such, the modulefiles usually set a `GCC_VERSION` variable which is used to resolve the relevant version of the application. This is set in the `gcc` modulefile, such that `module add gcc/6.4.0` would set `GCC_VERSION=6.4.0`
+
+# Using
+
+Choose a compiler version, and do
+
+```
+    module add gcc/<version>
+```
+
+_e.g._ :
+
+```
+    module add gcc/6.3.0
+```
+
+# Citing
+
+If you use this compiler in your toolchain, please cite :