Translight Photonic Crystal Modeling Software
by Andrew L. Reynolds
Translight 3.01 (for Windows, on Google docs)
Source code (zip, Google docs)
Translight Manual (pdf)
Cosmo VRML Viewer
I used to use this with Internet Explorer, but as noted on the NIST
link above, it may not work after April 2006. Following the instructions
on the NIST link above, I installed it successfully on Opera, though I
had trouble with Firefox (multiple tabs opened).