It made me wonder: why not rewrite
TeX.web in C++11? The codebase itself is now quite stable, and (unfortunately) it won't be too many more years before it's completely frozen.
I just downloaded the source; it's about 25,000 lines of WEB code. Let's say the code/comment ratio is 1/5, which results in around 5,000 lines of actual source code. At one line/minute hand rewrite, that's a little over two weeks. Even if these calculations are off a bit, it still seems like a "summer vacation" project.
Yes, I know there is a lot more than just
TeX.web. But it seems like a native C++ implementation (rather than a
web2c compiliation) could be an interesting step in a different direction.