For a complete installation, you will only need the first link. The “Complete” package contains instantOLAP, a preconfigured Tomcat server and all administration tools. If you only want to install the Workbench (the administration tool) on your computer, use the “Workbench” download.
The Linux version of instantOLAP also contains the software, a preconfigured Tomcat server and all administration tools.
Platform Independend Java Installer (Webstart)
You can use the following link to execute the latest version of the Workbench on your computer without installing it before.
Platform Independend Java Archives
Download this archives if you want to install instantOLAP in an existing Tomcat installation or if you want to update your existing instantOLAP server.