StoryBoard is a tool for tracking issues and tasks across multiple interrelated projects. It started out as an OpenStack Infrastructure project, and is currently used by a number of teams in the wider OpenStack project.
StoryBoard was designed to facilitate cross-project work in large communities like OpenStack. It contains a number of concepts familiar from other tools, with as many points of contention removed so as to ease collaboration between separate teams.
The most simple thing in StoryBoard is a single task. A task describes a single piece of work for a particular project. If the work involves writing code, then a task should map to a single commit. All tasks are part of a story. A story is a description of a feature or issue, and the tasks in a story represent the work needed in order to implement the feature or fix the issue. A story can have multiple tasks for multiple projects, allowing work of any size across any number of projects to be tracked in a single place.
In most task/issue trackers each item (for example a task) is given a single priority, which is set by either someone who claims responsibilty for the task, or management after discussions or prioritization meetings. This approach doesn't scale for situations where multiple distinct stakeholders may have equally valid and utterly different opinions on priority.
As an example, the lead of an open source project and the manager who is paying you to work on something in that project for your company may have conflicting opinions on what the priorities for the project should be, and obviously the project's work tracker will reflect the project lead's opinions.
In StoryBoard there is no global priority field for tasks. Instead, tasks can be added to worklists, which can be ordered however their users' see fit. This allows a person or group of people to assert the priority of a task to them by adding it to a worklist named "Alice's priorities", or "StoryBoard Team High Priority" for example.
Other folk can subscribe to these worklists if they care about those people's opinions on priority, and then see which of the worklists they're subscribed to contain a task when they are exploring stories and tasks.
This allows everyone's opinion of priorities to be tracked in the same place, and makes it easy to care about the opinion of multiple folk.
StoryBoard also provides a concept of boards, which are a flexible idea that can be used to track work using a kanban workflow, or used to further refine the idea of complex priority, or other things for which the ability to arrange tasks or stories into arbitrary lanes is useful.