diff --git a/.python-version b/.python-version
new file mode 100644
index 0000000..e4fba21
--- /dev/null
+++ b/.python-version
@@ -0,0 +1 @@
+3.12
diff --git a/README.md b/README.md
index 59c8e09..bbb38d2 100644
--- a/README.md
+++ b/README.md
@@ -66,25 +66,26 @@ We alter some of their Python code. Our experiments to combine it with Niedermay
 ideas to accelerate the computation of the matrix inverses did not yet justify
 the additional complexity.
 
-## Poetry
+## uv
 
-We assume you share already the love for [Poetry](https://python-poetry.org).
-Once you have installed poetry you can perform
+Starting with
 
 ```bash
 make install
 ```
 
-to replicate the virtual environment we have defined in [pyproject.toml](pyproject.toml)
-and locked in [poetry.lock](poetry.lock).
+will install [uv](https://github.com/astral-sh/uv) and create
+the virtual environment defined in
+pyproject.toml and locked in uv.lock.
 
-## Jupyter
+## marimo
 
-We install [JupyterLab](https://jupyter.org) on fly within the aforementioned
+We install [marimo](https://marimo.io) on the fly within the aforementioned
 virtual environment. Executing
 
 ```bash
-make jupyter
+make marimo
 ```
 
-will install and start the jupyter lab.
+will install and start marimo.
+