This is a Java servlet for building portals. You can use this servlet for developing your own portal as well as for portal running. Portal here is a set of individual portlets. Each portlet has got own attributes, including URL source. So any portal looks like a grid of portlets. You can select grid, size for the each cell (portlet) and of course a source (url) for the each portlet.

OpenPortal is a web portal framework that allows its users to personalise their web page on the site running this software. The users constructs his/her page by selecting between a set of portlets made available. A portlet can be a servlet or a JSP page.