Maybe WEFT has advanced, but when I was looking into it (couple years ago -- for displaying non-English web pages), it wasn't ready for primetime. It worked, but rendering was slow. When you selected a WEFT rendered text, it was noticeably slow -- and would crash the browser at times.

Turned out, we went back to what worked. Downloading TrueType fonts -- which also a problem, as different font are encoded for different code page.