ReportServer is described as 'web-based business intelligence platform that offers everything you need to evaluate your business. ReportServer comes with powerful ad-hoc analysis tools as well as with support for OLAP and pixel-perfect reporting'. There are more than 10 alternatives to ReportServer for a variety of platforms, including Windows, Online / Web-based, Linux, Mac and iPhone. The best alternative is Pentaho. It's not free, so if you're looking for a free alternative, you could try ART or BIRT. Other great apps like ReportServer are JasperReports (Paid), QlikView (Paid), Ubiq (Paid) and Sisense (Paid).
Pentaho is a Business Intelligence software company that offers Pentaho Business Analytics, a suite of open source products which provide data integration, OLAP services, reporting, dashboarding, data mining and ETL capabilities.
JasperReports is a variously-licensed reporting tool & library, written in Java, which can generate HTML, PDF, Excel, CSV, and other format reports. JasperReports Server Community Edition is Open Source, licensed under the GNU Affero General Public License 3 (AGPL v4).
Ubiq is a web-based Reporting and Business Intelligence application. It enables users to easily explore, visualize and analyze data. Users can quickly create reports and dashboards using data visualizations without any programming and share them with others.
ART is a web based reporting solution. SQL queries can be published in a few minutes. It supports tabular, crosstab, charts, scheduling, email alerts, drill down, among other features. Results are exportable to spreadsheet/pdf.
QueryTree is a flexible and powerful database reporting tool. Simply connect your database and start visualizing your data in minutes. Everything works with a dropdown menu interface - no code or SQL needed.
BIRT is an open source technology platform used to create data visualizations and reports that can be embedded into rich client and web applications. It is the Eclipse top-level project for Java based Business Intelligence.