Search Center
No Pre-Set Document Limits
Extensible Search Experience
Relevance Tuning
Continuous Propagation Indexing
Federated Search Connectors
Indexing Connectors
Security-Trimmed Results
Unified Administration Dashboard
Query and Results Reporting
Streamlined Installation
High Availability and Load Balancing
This list of features represents features included with the Enterprise Client Access License version of Microsoft Office SharePoint Server 2007. Some features will shortly be released as part of an Enterprise Search feature pack. Essentially, Search Server 2008 uses the same search engine used in SharePoint 2007. However, with SharePoint 2007 you also get the following features:
People and Expertise Searching
Business Data Catalog
SharePoint Productivity Infrastructure
The Express version and a trial version of the Enterprise version are available as free downloads from http://www.microsoft.com/enterprisesearch/default.aspx