Pasadena-based OpenX Technologies, a provider of ad serving software for web publishers, announced this morning that the firm has launched a new, advertising marketplace it is calling OpenX Market. According to OpenX, the marketplace will integrate with its software, and allow publishers to maximize their revenues. The new marketplace uses a real-time auction for impressions on web sites, comparing the ad rates for advertising through its marketplace with a publisher's own inventory, and running the one which will provide more revenue. The addition of the marketplace--which can be enabled in a software setting by publishers--puts the software firm in direct competition with companies such as Santa Monica-based Rubicon Project. OpenX Technologies is venture backed by Accel Partners, Index Ventures and O'Reilly AlphaTech Ventures.