It is a public website at http://digitalfire.com/4sight. It is a materials-centric traditional ceramics knowledge-base for formulating, adjusting and fixes glazes and clay bodies. He has been maintaining it since the early 1990s (it is generated by a content management system he develops). It has thousands of pages and tens of thousands of interlinks, and hundreds of its pages rank top-ten on search engines (people often arrive and use it unknowingly). Digitalfire desktop Insight software and Insight-live.com give people the calculation and data storage tools they need to make the best use of this library.
Glaze chemistry is the study of how the oxide chemistry of glazes relates to the way they fire. It accounts for color, surface, hardness, texturem, melting temperature, thermal expansion, etc.
Crazed ceramic glazes have a network of cracks. Understanding the causes is the most practical way to solve it. 95% of the time the solution is to adjust the thermal expansion of the glaze.
A downloadable program for Windows, Mac, Linux for doing classic ceramic glaze chemistry. It has been used around the world since the early 1980s.