The real-time inventory feature of Version 5.4 of the product makes it possible for both business-to-business and business-to-consumer sites to display in stock items in more visual ways.
This lets users know what online products are available, as well as side-stepping the often frustrating problem of filling out online forms only to find out that an item is out of stock.
"It also lets the vendors do 'availability of promise', which lets them sell items not yet in inventory but that they expect to be shortly," said Brian Adler, IBM's business-to-business segment manager for WebSphere.
The more advanced order management system helps streamline a number of business processes through features such as automated order status, which allows customers to track expected ship dates and automatically process backorders.
Another new capability is a personalised user interface which gives buyers and their partners a view into a business-to-business. The interface can be changed on a customer-by-customer or contract-by-contract basis.
A third feature is collaborative workspaces for business-to-business e-commerce designed to let parties exchange information more quickly by creating a "virtual teaming environment" where documents can be shared and edited.
Buyers and sellers can also administer and invite third parties into a collaborative workspace where they can share documents or engage in threaded conversations.
IBM has also improved the XML capabilities in WebSphere Commerce 5.
The WebSphere Commerce Professional Edition 5.4 costs $80,000 (£56,000) per processor. The Business Edition of Version 5.4 includes account and contract management features as well as advanced security control and costs $125,000 (£88,000) per processor.