I know in 1.8 (dunno about 1.7) there is a vanilla world border, which can be done via a command, and you can have it expand upon doing certain tasks (e.g. giving items, getting achievements, etc.)
Tinkers construct has a config option to set a world border. ForgeEssentials also has a world border module. Neither of those as far as I know can be edited with an item.
Tinkers construct has a config option to set a world border. ForgeEssentials also has a world border module. Neither of those as far as I know can be edited with an item.
That is a Bukkit plugin and does not work with Forge without Cauldron.