diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9fd26b301..7d94c648f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -183,6 +183,39 @@ When you run a locally built sbt, the JAR artifacts will be now cached under `$H
 
 One drawback of `-SNAPSHOT` version is that it's slow to resolve as it tries to hit all the resolvers. You can workaround that by using a version name like `1.$MINOR.$PATCH-LOCAL1`. A non-SNAPSHOT artifacts will now be cached under `$HOME/.ivy/cache/` directory, so you need to clear that out using [sbt-dirty-money](https://github.com/sbt/sbt-dirty-money)'s `cleanCache` task.
 
+### Running sbt "from source" - `sbtOn`
+
+In addition to locally publishing a build of sbt, there is an alternative, experimental launcher within sbt/sbt
+to be able to run sbt "from source", that is to compile sbt and run it from its resulting classfiles rather than
+from published jar files.
+
+Such a launcher is available within sbt/sbt's build through a custom `sbtOn` command that takes as its first
+argument the directory on which you want to run sbt, and the remaining arguments are passed _to_ that sbt
+instance. For example:
+
+I have setup a minimal sbt build in the directory `/s/t`, to run sbt on that directory I call:
+
+```bash
+> sbtOn /s/t
+[info] Packaging /d/sbt/scripted/sbt/target/scala-2.12/scripted-sbt_2.12-1.2.0-SNAPSHOT.jar ...
+[info] Done packaging.
+[info] Running (fork) sbt.RunFromSourceMain /s/t
+Listening for transport dt_socket at address: 5005
+[info] Loading settings from idea.sbt,global-plugins.sbt ...
+[info] Loading global plugins from /Users/dnw/.dotfiles/.sbt/1.0/plugins
+[info] Loading project definition from /s/t/project
+[info] Set current project to t (in build file:/s/t/)
+[info] sbt server started at local:///Users/dnw/.sbt/1.0/server/ce9baa494c7598e4d59b/sock
+> show baseDirectory
+[info] /s/t
+> exit
+[info] shutting down server
+[success] Total time: 19 s, completed 25-Apr-2018 15:04:58
+```
+
+Please note that this alternative launcher does _not_ have feature parity with sbt/launcher. (Meta)
+contributions welcome! :-D
+
 ### Diagnosing build failures
 
 Globally included plugins can interfere building `sbt`; if you are getting errors building sbt, try disabling all globally included plugins and try again.