Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

PracticePanther - PracticePanther offers CRM, invoicing, time tracking and communication solutions for law firms.

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.

Clio - Clio provides a full suite of web-based practice management tools targeted specifically at the administrative needs of sole practitioners and small firms.

Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.

MyCase - Practice More, Manage Less.