What is this kind of software called?
 

I'm looking for some kind of long-term project planner that lets me break down goals into tasks and tasks into sub-activities, and will produce a timeline, milestone tracking and calculate dependencies.

I'm sure there must be such a thing (and if there isn't, I'm running to the patent office ;)).

Thanks!

Try Microsoft Project. Doesn't work for everyone, but it does this kind of thing.

Most any of the project planning software will do it, Microsoft, Clarizen, etc.

Have you looked at the online tools included in zoho.com ?

Basecamp may also do what you need: http://www.basecamphq.com/?source=applist

project management software...theres a few titles kicking...

If you want Mac software, I've heard good things about OmniPlan and Merlin. There are more options as well, such as SharedPlan.

my wife likes this planner ... it is very flexible.

Reel Logix Calendar Planner

Project is fine for planning - just don't hit Auto Level. For tracking actuals and comparing to plan, it's a bit less competitive with some of the bigger packages.

Run away if anyone mentions Primavera.....;)

Viewpath.com lets you do this online. Specifically, I think you are looking for a Gantt chart. You can also use viewpath within spreadsheets in Google Docs.

If you want a Gantt project program, try "Ganttproject", open source and thus free.
We use it all the time at work for project management, even fairly complex tasks.

I find it easier to do it as a web project rather than using a desktop tool. Makes it much easier than sending a file back and forth.

If you are looking for something that you can run on your own webserver, try dotProject. It's opensource and free and I think it works very well.

Another free Gantt tool out there is at gantter.com.