A full list of all available patches can be found here.
Widescreen can be enabled by changing the ScreenHeight and ScreenWidth registry keys in HKEY_LOCAL_MACHINE\Software\Sierra On-Line\Cataclysm.
Widescreen mode requires the use of the OpenGL renderer as D3D has rendering errors with widescreen. Enabling OpenGL can be found further down the page in the "Issues Fixed" section.
For Windows 10 x64 you need to be run the program as Admin for the registry entries to be created (right click properties on the application under compatibility set run as administrator).
Add -window to the game's path. For borderless fullscreen windowed mode add -noBorder as well. If you do not use -noBorder you must run the game at less than maximum screen resolution or it will crash.
a. Use OpenGL rendering
b. Run the game with command line options /nofastfe /noglddraw
OpenGL rendering can solve severe lag problems in menus but in order to get OpenGL to work you need NT4 compatibility mode. This is problematic on Windows 8 and Windows 10 because NT4 compatibility mode is no longer offered by default. For Windows 8 and later use the Homeworld hardware acceleration fix to apply NT4 compatibility mode. Download the zip file. Extract the contents and follow the instructions in the readme.txt.
Simplest fix is to use the Windows shortcut SHIFT+WINDOWS KEY+ARROW KEY to move the game to the screen of your choice. You may have to alt tab back to the game afterwards.