How to get something like Dwarf Therapist running on a Mac

Taken from the project on Google Code

• Persistent custom professions - import and manage any number of custom professions across all your forts.
• Assign multiple dwarves to a custom profession at once to unify active labors
• Manage labors and professions much more easily than in-game using a flexible UI, allowing quick review of all dwarves at-a-glance
• Display all pending changes before they're written to the game
• Sort labor columns by associated skill level
• Persistent and customizable display; change colors, reposition/hide information screens
• Group your dwarves by several criteria

Doors can stop regular invaders, when the doors have been set to "forbid passage". Those doors can still be opened by thieves, who can pick the locks. Be careful though, because there are some monsters designated as "building destroyers" who have the ability to destroy doors entirely.

The best way I've found to stop things from getting in is with constructed walls. As in, breach the fun areas, then very quickly wall off that area until you are ready to deal with whatever you've found. Be quick with the walling though.

For more about doors, look here: http://df.magmawiki.com/index.php/Doors

For more about building destroyers: http://df.magmawiki.com/index.php/Building_destroyer