Minecraft Mod Examination: Journeymap, Opis, and Voxelmap
Despite being made of blocks Minecraft is a surprisingly good looking game and there are many people who enjoy exploring its infinitely expanding world. But those people quickly learn that the default create-able maps in Minecraft are really rather lacking in features. They are moderately expensive to make and only cover a fairly small area, and even when fully upgraded show roughly two zones worth of land if the "Large Biomes" setting is enabled. Even more problematic they are only at one zoom level and so a map large enough to be worth making will not display smaller or less visible structures. So nearly every mod-pack includes some map or other by default, usually either Journeymap, Voxelmap, or Mapwriter/Opis. While these three each provide fine maps, they do so in very different ways and are not always a good fit for all players.
But before anything else I should go over what all three of these maps have in common. Each one is a part of the interface and unlike the built-in maps does not have to be made. All three maps include some form of waypoints so one can easily find any place they wish marked even if it is too small to be shown on the map. They also have some kind of fullscreen map that can have those waypoints placed anywhere that the player clicks. The three maps generate waypoints when a player dies, showing the location of their death. All of them possess a minimap that can be disabled if the player wishes. And the three maps each have at least some degree of customization for both the minimap and the fullscreen map.
And let us start out with the favorite of most server admins: Mapwriter, and its close companion Opis. Mapwriter is a map mod that allows the viewer essentially unlimited retractable zoom, gives a trail option to show where the player has recently been, and can export the world map to a .png file. It also gives the player access to map markers group-able by name, which helps sort them well. But it is usually downloaded in a modified and more often updated form as part of another mod meant for server admins to use, Opis. Opis allows admins to better monitor their server and see which parts of their server are generating extra lag and gives them several tools to fix those issues. Unfortunately while the map itself is well done, the user interface manages to be simplistic yet somewhat unintuitive compared to the other two maps I am about to write about. There also is no option to show nearby creatures on your radar, or to display waypoints as beacons the way the next two maps do.
Whereas Mapwriter is oriented on being as much of a tool as it is a map, Journeymap specializes in giving the player as many options as they need to customize their experience. It includes all of the actual mapping features such as beacons, a full-screen map, a mini-map, radar, and the ability to export the world map into a file, but Journeymap also includes over a hundred options to adjust nearly every part of the experience. My favorite of its options is the ability to auto-map out all visited areas in a world even if such data is lost thanks to Minecraft crashing, and while Mapwriter does have this option it is harder to find in the interface and can be somewhat unreliable. The only significant flaw with this map for personal use is that it has a fairly close maximum zoom, meaning that if you like going on very long journeys, this might not be the map for you.
Finally we have Voxelmap, the only one of these map mods currently available for Minecraft version 1.8.X. Voxelmap is generally considered to have the lightest load of the three maps, has a clean interface, and while it lacks some of Journeymap's customization, it still has nearly all of the same features. It should be noted however that while the other two mods require Forge, Voxelmap uses another, forge compatible mod loader called Liteloader, and both it and Voxelmap can sometimes have weird conflicts with some other mods. The only other issue one might have with Voxelmap is that it seems to lack an export to file option, so if you want to share a picture of your world with others you will need to generate it in some other way.
While each of these three map mods are fairly popular, depending on your playstyle and needs there are plenty of reasons to chose one over another. Voxelmap can have some issues with new dimensions like the Lord of the Ring's mod's Middle-Earth, but it is quite lightweight and works very well for someone playing in Minecraft's normal three dimensions. Meanwhile Journeymap plays better with other mods and has a lot of customization, but is a bit heavier on the system. And Mapwriter/Opis is certainly the best option for a server administrator, and should also be considered for larger online world or for anyone who wants to explore more than a couple of thousand meters away from home. They are all good and worth messing with, and any of them will prove more useful than the vanilla map.