Open Source C++ Charting Library for Linux/Solaris

[David Smith]

I'm looking for a decent open source charting library for Linux and
Solaris, BSD/LGPL-style license preferred. I need to do simple pie charts
and bar graphs, but they need to be pretty. There doesn't seem to be a
whole lot of options out there, and what I have found is buggy and/or
ugly. I found a commercial offering called ChartDirector, which works
pretty well, but lacks source. Anyone have an idea?

--Dave