Thank you for the warm words!
Sometimes google places RefractiveIndex.INFO on the second position, but not as often as I would like to...
Temperature dependence of the refractive index is certainly something I always keep in mind when thinking about the future of the database. Current format of the underlying database is pretty ugly and does not support any variables except wavelength. Now I am trying to develop a better, more flexible, XML-based format suitable for representing refractive index as a function of an arbitrary number of variables, that would allow in particular to include data on temperature dependence. Another feature of the new format should be the possibility to include any constants, not only refractive index and extinction coefficient like now. I am planning to make the database in the new format publicly available under the LGPL license and hope that this will motivate people to contribute into the database development (actually, I already received quite some input from the community, including pointing out the need for such a universal database). This is however a long-term project: can easily take many months before something working is ready. At certain point I will ask the community for input regarding making the new format suitable for different applications, as well as for contributing new data.