Some of my favorite programs are written in Java!
This one has been getting my attention lately:
The Java API Reference Manuals at Sun.
The Java Tutorial at Sun.
Gamelan at developer.com.
... PBM author Jeff Poskanzer has a name your can trust.
Math and Graphs
I am trying to find Java sources for a decent scientific plotting
package, with things like autoscaling, log axis, markers, zoom, and pan.
The graphing applets I have seen do not have nearly enough capability to
make them better than dumping bitmaps from an established package such
as gnuplot. The applets I've seen also look like they were fairly
difficult to code. It almost seems like we're back in the dark days of
the IBM PC before an affordable, usable graphics subroutine library was
written in Turbo Pascal.
It is amazing that there isn't something like Gnuplot in Java.
There are business graphics, and web statistics graphics, but
the work on scientific plotting has not reached the mainstream.
... Home of NetCharts
WebEQ has several approaches to equation rendering and
a nice summary of the tradeoffs in presenting math on the web.