diff --git a/python-perfs/include/collatz_length.py b/python-perfs/include/collatz_length.py
index a265716..314123d 100644
--- a/python-perfs/include/collatz_length.py
+++ b/python-perfs/include/collatz_length.py
@@ -3,5 +3,5 @@ def collatz_length(n):
         return 0
     if n % 2 == 0:
         return 1 + collatz_length(n // 2)
-    elif n % 2 == 1:
+    else:
         return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/include/collatz_length_annotated.py b/python-perfs/include/collatz_length_annotated.py
index 89b1ec1..123d8d9 100644
--- a/python-perfs/include/collatz_length_annotated.py
+++ b/python-perfs/include/collatz_length_annotated.py
@@ -6,5 +6,5 @@ def collatz_length(n: cython.uint) -> cython.uint:
         return 0
     if n % 2 == 0:
         return 1 + collatz_length(n // 2)
-    elif n % 2 == 1:
+    else:
         return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/include/collatz_length_mypy.py b/python-perfs/include/collatz_length_mypy.py
new file mode 100644
index 0000000..c7c93ef
--- /dev/null
+++ b/python-perfs/include/collatz_length_mypy.py
@@ -0,0 +1,7 @@
+def collatz_length(n: int) -> int:
+    if n == 1:
+        return 0
+    if n % 2 == 0:
+        return 1 + collatz_length(n // 2)
+    else:
+        return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/include/collatz_length_nuitka.py b/python-perfs/include/collatz_length_nuitka.py
new file mode 100644
index 0000000..314123d
--- /dev/null
+++ b/python-perfs/include/collatz_length_nuitka.py
@@ -0,0 +1,7 @@
+def collatz_length(n):
+    if n == 1:
+        return 0
+    if n % 2 == 0:
+        return 1 + collatz_length(n // 2)
+    else:
+        return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/include/collatz_length_numba.py b/python-perfs/include/collatz_length_numba.py
index 5d47c60..e2c74a2 100644
--- a/python-perfs/include/collatz_length_numba.py
+++ b/python-perfs/include/collatz_length_numba.py
@@ -7,5 +7,5 @@ def collatz_length(n):
         return 0
     if n % 2 == 0:
         return 1 + collatz_length(n // 2)
-    elif n % 2 == 1:
+    else:
         return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/include/collatz_length_pythran.py b/python-perfs/include/collatz_length_pythran.py
new file mode 100644
index 0000000..4654c21
--- /dev/null
+++ b/python-perfs/include/collatz_length_pythran.py
@@ -0,0 +1,8 @@
+#pythran export collatz_length(int)
+def collatz_length(n):
+    if n == 1:
+        return 0
+    if n % 2 == 0:
+        return 1 + collatz_length(n // 2)
+    else:
+        return 1 + collatz_length(n * 3 + 1)
diff --git a/python-perfs/perfs.md b/python-perfs/perfs.md
index c4f8df8..41dd3b7 100644
--- a/python-perfs/perfs.md
+++ b/python-perfs/perfs.md
@@ -444,9 +444,9 @@ $ python -m pyperf timeit \
 
 ```shell
 $ cythonize --inplace collatz_length.py
+#!cythonize --inplace include/collatz_length.py
 ```
 
-#!cythonize --inplace include/collatz_length.py
 
 ```shell
 $ python -m pyperf timeit \
@@ -518,10 +518,69 @@ $ python -m pyperf timeit \
 
 # mypyc
 
+mypyc est un compilateur qui s'appuie sur les annotationes de type mypy :
+
+```python
+#!cat include/collatz_length_mypy.py
+```
+
+## mypyc demo
+
+```shell
+$ mypyc include/collatz_length_mypy.py
+#!mypyc include/collatz_length_mypy.py
+```
+
+```shell
+$ python -m pyperf timeit \
+> -s 'from collatz_length_mypy import collatz_length' \
+> 'collatz_length(837799)'
+#!cache -- python -m pyperf timeit --fast -s 'from collatz_length_mypy import collatz_length' 'collatz_length(837799)'
+```
+
+
 # Pythran
 
+pythran est un compilateur pour du code scientifique :
+
+```python
+#!cat include/collatz_length_pythran.py
+```
+
+## Pythran demo
+
+```shell
+$ pythran include/collatz_length_pythran.py
+#!pythran include/collatz_length_pythran.py
+```
+
+```shell
+$ python -m pyperf timeit \
+> -s 'from collatz_length_pythran import collatz_length' \
+> 'collatz_length(837799)'
+#!cache -- python -m pyperf timeit --fast -s 'from collatz_length_pythran import collatz_length' 'collatz_length(837799)'
+```
+
+
 # Nuitka
 
-# https://github.com/pfalcon/awesome-python-compilers
+Aussi un compilateur, aussi utilisable pour distribuer une application.
+
+```shell
+$ python -m nuitka --module collatz_length_nuitka.py
+#!python -m nuitka --module include/collatz_length_nuitka.py >/dev/null
+```
+
+```shell
+$ python -m pyperf timeit \
+> -s 'from collatz_length_nuitka import collatz_length' \
+> 'collatz_length(837799)'
+#!cache --force -- python -m pyperf timeit --fast -s 'from collatz_length_nuitka import collatz_length' 'collatz_length(837799)'
+```
+
+
+# Et d'autres
+
+https://github.com/pfalcon/awesome-python-compilers
 
 # Hand crafted C
diff --git a/python-perfs/requirements.txt b/python-perfs/requirements.txt
index e81edb7..ebe0c3c 100644
--- a/python-perfs/requirements.txt
+++ b/python-perfs/requirements.txt
@@ -3,3 +3,6 @@ cython
 snakeviz
 scalene
 numba
+mypy
+pythran
+nuitka