from lightweight languages to heavyweights

Paul Graham has mentioned a few times that Yahoo rewrote his ViaWeb 
code from lightweight languages (let's admit CL for the sake of the 
argument with the LL camp, a lot of code was a in a "true" lightweight 
language) to C++. We can speculate why they did this, whether it was 
good or bad. I am not interested in any of this.

My question is: do any of you know of other examples of rewriting 
successful applications from a lightweight language into a heavyweight 
language? I would be interested to know a few. Descriptive answers are 
preferred over opinions.

-- Matthias