I am looking for a cross-platform library in C / C ++ that can schedule tasks, function calls, etc. It would be nice if it were closer to Java Quartz. I would prefer BSD style licenses, LGPL will be fine too.
Libevent: http://www.monkey.org/~provos/libevent/ is probably too heavy for your use case, but you can decide for yourself if it works for you.
Edit: This is more about scheduling features after certain timeouts within a program. Looking at the quartz, it seems to be wider. Therefore, I doubt libevent is what you are looking for.