Although, most of the Sublime core is in C/C++ as far as I know. And it's using native drawing, not webkit. Will be interesting to see how the performance compares.
sublime is using opengl to render every glype. Its speed will blow anything out of the water. Open 2MB text will be highlighted and colored in an instant. I wonder how could webkit achieve that.
My suspicion is sublime's speed has very little to do with its rendering method and a lot more to do with its I/O philosophy. Because, let's be honest, there is no way OpenGL can make loading a 50mb file into memory significantly faster than plain rendering.