Jira may be extremely sluggish and require a large amount of memory on the client side.
Confluence - Confluence is content collaboration software that changes how modern teams work
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Slack - A messaging app for teams who see through the Earth!
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Yammer - Yammer is a leading enterprise social network used by more than 200,000 companies worldwide, including 85% of the Fortune 500, to get work done smarter and faster. Sign Up Today.
Basecamp - A simple and elegant project management system.