If you download the trial for LiveCycle Data Services ES, from http://www.adobe.com/cfusion/tdrc/index.cfm?product=livecycle_dataservices you will see there is a 120 day trial license key, and if you omit the the key you get a Developer License that is the equivalent of the Express edition on 2.6
Starting LCDS 3.0, we don’t offer the express edition. If you don't provide a license key, the server defaults to a developer license. The developer license is free for developers to use in development and not to be used in production. The server is limited to accept only 3 concurrent connections.