This is where any files that COULD cause incompatibilities will be placed. These files are optional, meaning that the game will work without these.

xg.class:
Modifies the BlockFire file so Smooth Netherrack will burn continuously, just like normal Netherrack.

dynamiclights.settings:
Place in the .minecraft folder. This properties file is optional, and will only work if you have Dynamic Lights installed. If you have dynamic lights installed, you can use this premade settings file to make things such as foulite torches and glowood and other glowing things shiny. If you would like to download DynamicLights, or to learn more about DynamicLights, please visit this URL:
http://www.minecraftforum.net/viewtopic.php?f=1032&t=199815