Remember The Milk alternative that is not “in the cloud”?

Question

I use RTM for my personal task management, and I love it. I'd love to use it for work as well but my company has policies that do not allow me to put company data onto external services. I currently use OneNote for task management for work, but I find it a poor substitute for RTM. Is there a RTM equivalent that is either installed on my local machine as desktop software, or could be installed on an internal web server?

Edit:
Some clarifications:

• I am on Windows (preferably something that would work with XP and Win7)
• Although I like everything about RTM, I am specifically interested in the "virtual folders" (search folders or whatever they are actually called) that lets you put together things like a "Due Today" list across all your actual lists.

Answer 1

Some of the alternative that you should try

1. Wunderlist:Wunderlist is a free, open source, simple and beautiful cross-platform task management tool that lets you sync your to-do list between different computers and devices
2. Remember The Task:Remember The Task is a light-weight ToDo application that allows you to maintain a list of tasks to be done. It Syncs with Remember The Milk so you can manage your tasks on the go using RTM.
3. Todo.txt:Track your tasks and projects in a plain text file, todo.txt. A todo.txt is software and operating system agnostic; it's searchable, portable, lightweight and easily manipulated.
4. ToDoList:A simple but effective way to keep on top of your tasks. ToDoList is a rare form of task management tool, one that allows you to repeatedly sub-divide your tasks into more manageable pieces whilst still presenting a clean and intuitive user experience.