Ultima Thule: Writer's Database
WriteDB is a database system that enables writers to keep track of the works they have created, the potential publishers they have identified and any submissions to those publishers.

Write Again
Writing management tool. Helps writers, poets, freelancers and other literary artists manage their projects, markets/contacts, submissions, deadlines and finances.

The Writer's Database: Submission Tracker
A free web-based database for writers to keep track of markets and submissions sent out.