Todoman is a simple, standards-based, cli todo (aka: task) manager.

Todos are stored into icalendar files, which means you can sync them
via CalDAV using, for example, vdirsyncer.

Todoman is now part of the pimutils project, and is hosted at GitHub.

Autocompletion files can be installed with :
BASH_AUTOCOMP=yes (enabled by default)
ZSH_AUTOCOMP=yes (enabled by default)