Here the changes list:

1.8 New version '08. This version requires DirectX December 2007 update. Added Updated interface. Full Windows Vista support (XP still supported). DirectX 10 support. DirectX 9EX support (WDM Vista). MacOSX 10.5 improved support. Faster sky rendering. 4 times more stars. Terrain rendering in local view. Planets with level of detail. Satellites rendering using TLE database. HDR (high dynamic range) rendering Multiprocessor/multi core optimised.
1.6.7 Final version before SkyORB 07. Fix compatibility with MacOSX 10.3.9 (compatible DMG format and removed OpenAL dependency). Fix clip plane in local view (DX9 and OpenGL/PC). Few speed optimisations when zoom in (OpenGL). Improvements in shaders (DX9, OpenGL).
1.6.5 This update is for Win32 only. Fixes widescreen resolution in 1650x1050. Fixes problems running the application due to the upgrade to Visual Studio 2005 SP1 (Side by Side configuration error). If the program stills not running, try to install the Microsoft Visual Studio 2005 Redistribution Package.
1.6.4 Resolution independance (works in 640x480 or 1600x1200 or higher). Bug fixes in OpenGL, Direct3D and Software renderers for Intel and nVidia chipset. Improved software update mechanism.
1.6 First public release. New user interface, optimized for 1280x1024. New local view, with improved sky rendering and improved accuracy when rendering sky from other planets like mars, or mercury. Larger star database (>60000 stars, all the HYG with magnitude 8.5). Larger deep space objects database. Uranus and neptunian moons. Many bug fixes and improvements. Support english, french, german and russian.
Also updated engine: Windows: Multi-threaded optimised, New Direct3D 9.0 renderer, entirely using HLSL, For Windows XP (x86/SSE and x64/SSE2 - Fully optimized for AMD64 X2). MacOSX : Multi-threaded optimised, taking fully avantage of Dual G5 and Intel Core Duo. Universal binaries (x86/SSE2 and PowerPC/Velocity Engine optimized) New OpenGL rendererer, OpenGL 2.0 features optimized (hardware point sprites, GLSL) - Compatible with MacOS X 10.4 or better only.
1.5.4 (Windows only) Now using DirectX 9.0C (Standard version). Native 64-bit version for Windows x64. Bug fixes in OpenGL, Direct3D and Software renderers.
1.5.2 Removed dependencies on DirectX 9.0 August 2005 (now uses DirectX 9.0c Standard). Improved stability in full screen with DirectX 9.0c and resolution switching.
1.5.1 Public release, Added search engine, Added fullscreen effects (bloom rendering), Several bug fixes, Available for Windows and MacOSX 10.4. DirectX 9.0C June 05 Update required for DirectX rendering (installer is now provided). Fixed software renderer.
1.5.0 First beta release : Improved MacOS X support, Updated software renderer (PC version) with MMX and SSE2 support, Ability to update MPC from application (no need of mpc2xml.exe anymore), Version checking, Saturn now produces shadows on the rings, Added more Saturn moons, Reliable Saturn, Mars and Jupiter moons position computations, Updated DirectX and OpenGL support (ATI R200 renderpath), Faster loading time, Bigger star database (based on HYG v1.1).