Report Manager has been around for quite a few years. It's written in Delphi (at least it was originally) and has components that can be used in Delphi, but is usable via ActiveX or dll from just about any language. Now has a native .NET library too. Has a nifty report-serving webserver you can set up too. The designer gui looks and feels a little rough around the edges but it works.
http://reportman.sourceforge.net/
