Doit.im

Doit.im is a free cross-platform program that allows you to manage your pending tasks according to the GTD (Getting Things Done) method, allowing you to store your data online so you can access them anywhere.

Its interface is simple and convenient to use, and visually looks a lot like apps you would find on Max OS X. It has a menu bar with an integrated search and where you can view your pending tasks.

You can add notes, tags, deadlines, and a repeat cycle to each task you create.

You can create projects and group together tasks that relate sequentially, and manage them either by project or each task individually.

Also, Doit.im allows you to collaborate with one or several users by sharing tasks with them.