I'll pitch in with my stack too!
Engine: The Full-Custom Hastily-Thrown-Together Lumps of Source Code Mk. 2 (Custom C++ base using GLFW and GLAD)
3D: Blender
2D: Aseprite (Going for low-res pixel art textures to save time)
Music/SFX: OpenMPT, Famitracker, BFXR.