[gsnedders]

Carakan was 16.5 months from first commit to shipping (and a month or so more to not being notably buggy), with a team of five for the vast majority of that time. The only code carried over verbatim from Futhark was the regexp engine (though that had machine-code generation added to it), and the parser was also pre-existing (though not shared with Futhark!).

For comparison: MS were the last to do a major rewrite of their layout engine, which started, AIUI, before IE7 shipped (Oct 2006) and shipped in IE8 (Mar 2009), and more-or-less reached feature parity with others with IE9 (Mar 2011). To be fair, they were working from a far more archaic codebase than anyone else, so probably had more work, but they also had a far larger team than anyone else working on this.

[bzbarsky]

When discussing timeframes, it's important to keep the moving goalposts in mind.

Back in 2009 it took order of 16 months to write a competitive JIT. But today's JITs are a good bit faster than they were in 2009, which means more special cases that need to be considered and made fast, from what I've seen of JIT development.

I should also note that I included QA resources of various sorts in my team size estimate....

[gsnedders]

Right: I think if Carakan were done now it would likely take two years to being competitive, given the same team size (and I included QA in team size — varying between 1.5 and 2).