Sharepoint Excel Service

Excel Services is a Microsoft Office SharePoint technology that makes it simple to use, share, secure, and manage Microsoft Office Excel 2007 workbooks as interactive reports in a consistent way throughout the enterprise. Excel service empowers the users to publish and run spreadsheets on the server which enables the users to access these spreadsheets through a web browser without need of custom browser component. Basically, excel allows you to add spreadsheets and workbooks to your enterprise dashboard and portals. Excel services which is a part of Microsoft SharePoint server 2007, enhances the ability of Microsoft office excel 2007 to re-use the spreadsheet models. Excel services is a part of Microsoft Office SharePoint Server 2007 and built on ASP.NET and WSS 3 technologies. Following are the core components of the Excel Services: Excel web services Excel web access Excel calculation services

Excel Service Office 2007
Excel web access is a web part that displays data and chart Excel workbook with the same appearance. The sheet tabs, outline buttons and drop down arrows in excel web access can be customized in a different ways. Excel web service is hosted in Microsoft Office Sharepoint Service that provides several methods that a developer can use as an application programming interface to build custom applications based on the Excel workbook. Excel calculation services load workbooks and calculate it, refreshes external data and maintains the sessions.

http://www.zimmergren.net/archive/2007/05/09/simple-excel-services-step-by-step-publishing-a-spreadsheet-to-sharepoint-2007.aspx

http://www.codeproject.com/KB/sharepoint/DisplayingCharts.aspx