There are a few. Stonesense is a piece of visualization software.
Dwarf Therapist is probably the single most important helper program to get. It allows you to quickly and easily assign and unassign jobs to your dwarves. But that's pretty much it for adding to the interface.
DFHack is a collection of hacks, some of which will help to automate some of the more tedious parts of the interface
The workflow hack, for example, lets you set the minimum and maximum number of things your fortress should have for any given thing -- so it will add jobs when you run low, and remove them when you hit your max. However, once you get used to the manager interface in the game, this looses a lot of it's luster, because it's not really all that hard to get everything you will ever need in any given category by year two or three. You'll be amazed at how much food you can grow on 12 squares with one grower, especially once you start cooking.
The vein digger hack is probably the best hack out there, from a automate the tedious parts standpoint. You put your cursor over one tile of a vein, trigger the hack, and the whole vein is designated to be dug out -- even the parts you can't see yet.
But, mostly DFHack is about hacks. Making lava for your magma forges without having to transport it via insane pumpstacks, cleaning contaminants, making trees grow -- that sort of thing.
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So, there are two things I'm going to point you to:
The
Lazy Newbs Pack and the
Masterwork Mod. Both come with bundled launchers that will launch the game and DFHack, dwarf therapist, and a few others. Masterwork is a great mod still in progress that removes some things (like a million and one stone types that are virtually identical), but adds still more (such as more monsters, more weapons, more traps). Both allow you to sub in a new font as a 'graphics pack' to make visualizing the game quite a bit easier if you're not already familiar with rogue-likes. I would recommend Lazy Newbs Pack first, simply because when you run into questions (and you will), the answers will be on the
Wiki and when you ask on the forum, most people will know what the heck you're talking about.
Once you can drive a fort into the ground intentionally, then you can start branching into mods, because then you can probably answer most of the questions that pop up yourself.