Remember the Milk (RTM) is an application service provider for a Web-based task- and time-management.

Todoist: To-Do list and Task Manager.

Glip is fully searchable, real-time group chat; video chat, task management, file sharing app.

Habitica (HabitRPG) is an online task management application.

Taskulu is a Flexible task management, realtime chat, time logs and deep integrations.

Checkvist helps you create and share online outlines, project plans, online checklists, and task lists.

Dapulse is a smart collaboration and communication app you can use to get your team members working in sync in one place.

Wrike is an online project management software that gives you full visibility and control over tasks.

Toodledo is a popular and powerful online productivity tool. Manage your to-do list, take notes, track habits, and organize ideas into outlines and lists.

OmniFocus is a personal task manager.

Sandglaz's agile boards help you accomplish more with less stress.

Avaza is a beautiful online software suite with modules for Project Management, Timesheets, Expenses & Invoicing. Access from anywhere, with any device.

Conqu is a simple yet powerful task management tool designed to help you conquer your inbox and get things done.

Notebooks is a note taking and task management app.