diff --git a/service/documentation.md b/service/documentation.md
index 7b3f7a1ecb27d75075cc62d1ad6126b3e96336f8..ed608661ce8d87c3e020a600f0b4c1213f794028 100644
--- a/service/documentation.md
+++ b/service/documentation.md
@@ -677,3 +677,5 @@ We currently use [Graphviz](https://graphviz.org/) to draw charts, but have also
  * [Mermaid](https://mermaid-js.github.io/mermaid/#/) - builtin to GitLab and GitHub
  * [Knotend](https://www.scottantipa.com/why-knotend)
  * [Flowchart](https://flowchart.fun/)
+ * [Kroki](https://kroki.io/) does basically all of those, and [niolesk](https://niolesk.top) is a web
+   app on top of that