The TnL has a big change in the lightning engine. Now it supports the specular reflectance model, no acceleration yet. That's why we moved to v3.0

You have just to recompile your program if it uses the "xLight" engine to be able to use versions 3.x

You may need to tell the API (Direct3D, OpenGL) that you want to use specular lightning

TnL: Macro "_SKIP_ALPHA_CALC" was actually enabling, not skipping, alpha calculations in src/TnL/Lights.c