Software vendor Niku has launched an open source version of its Workbench Windows desktop-based project scheduling software, aiming to attack the market dominated by Microsoft Project.

Open Workbench can be accessed free of charge, and the source code will be available for access and amendment at SourceForge next month, covered by the Mozilla open source licence.

The existing Workbench product boasts 100,000 users within blue chip companies, including HSBC, Philips, BT, Unilever and Visa International. It is currently being rolled out to 19,000 HSBC users worldwide.

Open Workbench can import Microsoft Project-format files to make migration of projects and interworking easier.

"Project scheduling has become commoditised but is a critical tool for project managers," Niku's vice president of global marketing, David Hurwitz, told vnunet.com.

"So this is a terrific thing for our customers and will bring headaches to some of our competition, especially Microsoft."

Gartner analyst Matt Light said in a statement: "Open source project schedulers will allow vendors to focus on meeting the demand for more complex applications: portfolio management [and] IT governance and control."

Light estimated Microsoft's revenues from desktop project scheduling tools at "nearly $1bn".

Through the move, Niku also hopes to sell more of its high-end server-based Clarity software, with which Open Workbench integrates.

Clarity runs on Unix or Windows and combines portfolio planning and analysis with project, programme, financial and process management.

Hurwitz said there had yet to be any demand for a Linux version of Open Workbench but that, if the open source community wanted to create one, "[Niku] would love that".