Note: Download RML Utilities for SQL Server by Microsoft
The RML utilities allow you to process SQL Server trace files and view reports showing how SQL Server is performing. For example, you can quickly see:
You can also test how the system will behave with some change (different service pack or hotfix build, changing a stored procedure or function, modifying or adding indexes, and so forth) by using the provided tools to replay the trace files against another instance of SQL Server. If you capture trace during this replay you can use the tools to directly compare to the original baseline capture.
Supports SQL Server versions 2000, 2005 and 2008.
Abstract courtesy : Microsoft
Reference: Pinal Dave (http://www.SQLAuthority.com)