diff --git a/CHANGELOG.md b/CHANGELOG.md
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@@ -1,5 +1,15 @@
 # Changelog
 
+## 0.5.x
+### **OPTIMA35 0.5.0: Code Cleaning and Preparation for Split**
+- Cleaned up the codebase, following **PEP8**, adding indication for only internal functions.
+- Refactored the project in preparation for splitting it into **OPTIMA35 (core functionality)** and **UI (graphical and text interfaces)**.
+- Moved `image_handler.py` into the `optima` folder/package to integrate it as an essential part of the OPTIMA35 package, rather than just a utility.
+
+### **UI 0.1.0: GUI and TUI Updates**
+- Updated **GUI** and **TUI** to work seamlessly with the new **OPTIMA35** class.
+- Ensured compatibility with the newly organized codebase in the OPTIMA35 package.
+
 ## 0.4.x
 ### 0.4.1: Finished GUI and TUI
 - Both **GUI** and **TUI** now fully utilize the `optima35` class for core functionality.