[fspeech]

Here is an interview talking about the move to ChezScheme https://www.notamonadtutorial.com/rebuilding-the-racket-comp...

"Why did you choose Chez Scheme over other Schemes to rebuild Racket?

The biggest weakness of the Racket BC (“before Chez”) implementation are its back-end compiler structure, its inefficient internal calling conventions (over-adapted to C), and its poor implementation of first-class continuations. Those are exactly the strengths of Chez Scheme. Furthermore, Racket’s evaluation model was always closely aligned with Chez Scheme, such as the emphasis on interactive evaluation and compilation.

It was clear up front that Chez Scheme lacked significant features that Racket needs, such as support for continuation marks and reachability-based memory accounting. However, the high quality of the Chez Scheme design and implementation, in contrast to old Racket’s implementation, made adapting Chez Scheme more appealing than retrofitting Racket’s old implementation further."

And much more.