Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Unfuddle - Unfuddle is a secure, hosted project management solution for software development teams.
Basecamp - A simple and elegant project management system.
Backlog - A cloud-based project management app for developers and their teams.
Cage - A simple way for designers and teams to share, manage and approve their creative work.
Axosoft - Axosoft is proprietary software for project management.