Rockstar has announced that Patch 6 for the PC version of Grand Theft Auto IV will be available on Games for Windows LIVE very soon. The patch will include all the enhancements found in the PC version of Grand Theft Auto: Episodes from Liberty City, which releases tomorrow in North America.

The most significant changes are the removal of the Social Club application required to launch the game, and enhanced multiplayer security to protect against cheaters. The Moon, which has been absent in the PC version up until now, is available "with simulated lunar phases". Oh boy!

The full list of changes is shown below:

Rockstar Games Social Club

• Remove Rockstar Games Social Club application
• Separate RGSC application no longer required to launch game
• Social Club login now occurs during the launch process

Shadows

• A new, less memory-intensive, and better-looking scalable shadow solution has been implemented
• Enhanced Night Shadows added with user-selectable level of detail (replaces Shadow Density)

Performance

• Rendering optimizations have been made to improve performance, particularly when enabling shadows
• User-configurable graphics settings have been added for shadow control
• Improved memory management

Multiplayer

• Enhanced security to isolate users from cheaters and hackers

Episodic Content

• Provide in-game support to purchase "The Lost and Damned" and "The Ballad of Gay Tony" (Not available in Russian/Japanese Versions)

Bug Fixes

• Vehicle shadows re-enabled between 8pm and 6am
• Fix floating street textures
• Pedestrians in vehicles appear further out from the player to allow for long range sniping
• The Moon has been implemented with simulated lunar phases
• Fixed garbled text in Japanese Multiplayer menus
• "RESC 10" error fix for specific hardware configurations

Link: GTA IV PC Patch 6 Announcement.