SQL Server Reporting Services (SSRS) is part of the SQL Server suite and is a server based report generation tool. It has been included with SQL Server since version SQL Server 2005 (available for SQL Server 2000 as an add-on download). It is one of the options during the installation process and can be added at any time. SSRS provides a drag and drop report builder for the novice or advanced users can use Visual Studio to create reports. Subscriptions can be configured for reports and deployed to users via e-mail. The reports can be sent or saved in various formats including CSV, Excel, PDF, TIFF, Word or XML. Users can also run the reports on demand by accessing the SSRS site in combination with their Windows Authentication.
So if you have an off the shelf application that utilizes SQL Server as the backend but the application is not fulfilling all of your reporting needs; look to SSRS, it is already a tool you have.