ExcelWriter from SoftArtisans is a server-side spreadsheet-reporting library that lets you deliver native Excel documents over the Web. Running multiple Excel instances on a Web server introduces performance and stability problems, as well as licensing issues. You deploy ExcelWriter to a Web server as a single multithreaded COM DLL capable of handling concurrent user requests reliably—with no per-user license cost, and without running Excel on the server.

You create an instance of the ExcelWriter application class to gain access to an object model quite similar to Excel. You populate the Cells collection and execute the Save method to create an Excel spreadsheet on the fly from scratch and stream it to the client (see Figure 1). You also can change an existing Excel document or template before streaming it to the client. ExcelWriter supports formatting, formulas, custom styles, charting, and images. The object model also supports advanced Excel features such as macros, outlines, PivotCharts, and Visual Basic for Applications (VBA) code. It generates Excel files in native Microsoft binary format compatible with Excel 95, 97, 2000, and 2002.

The CopyFromRecordset and GetDataFromRecordset methods transfer a rectangular block of data from an ADO RecordSet to a spreadsheet in a single step. Version 4's new GetDataFromDataset method provides the same support for an ADO.NET DataSet. ExcelWriter also can use data it parses from an XML data source to furnish a spreadsheet.

Client users can modify spreadsheets and upload the changes to the server. HotCell technology—a new feature in version 4—lets local modifications update data on a Web server dynamically.

ExcelWriter's Enterprise Edition provides the full feature set and unlimited spreadsheet delivery. Standard Edition has a reduced object model, can't manipulate Excel files, can't post workbook changes back from the client to the server, doesn't include the HotCell feature, and doesn't provide full .NET support. Limited Edition has the same limitations and a delivery limit of 200 spreadsheets per day. A developer version of each edition that can generate only one spreadsheet at a time is also available. It includes CodeWizard —a handy component that examines an Excel file and generates a source file containing the code necessary to reproduce it. The SoftArtisans Web site posts a detailed comparison of the editions to help you decide which one suits your needs.

Setup is fast and simple. The help files include a quick-start tutorial, plentiful samples, and in-depth feature coverage. ExcelWriter is powerful and easy to use, offering a practical solution for your Web-based spreadsheet-reporting needs.