The best open source alternative to Crystal Reports is Seal Report, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Crystal Reports and 13 is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Crystal Reports are EDA (Paid, Open Source), FastReport Open Source (Free, Open Source), ART (Free, Open Source) and DynamicReports (Free, Open Source).
QtRPT is the easy-to-use print report engine written in C++ QtToolkit. It allows combining several reports in one XML file. For separately taken field, you can specify some condition depending on which this field will display in a different font and background color, etc.
Multi-platform C++ report generator library written using Qt framework and intended for software developers that would like to add to their application capability to form reports or print forms generated using templates.