DynmapForge Mod 1.8, 1.7.10, 1.7.2 is the Forge version of the popular Dynmap plugin for Bukkit.

A Google Maps-like map for your Minecraft server that can be viewed in a browser. Easy to set up when making use of Dynmap's integrated webserver which works out-of-the-box, while also available to be integrated into existing websites running on Apache and the like. Dynmap can render your worlds using different renderers, some suitable for performance, some for high detail.

Components allow you to add/remove functionality to make Dynmap suit your needs. Using the components Dynmap comes supplied with, there is support for chat balloons, web-to-game chat, and configurable markers, areas, and lines.