Hi Folks, I've successfully finished the Spur conversion of Cuis. I was able to merge all required changes to Cuis compiler and make it work in both ObjectMemories. Cuis is now offered in Spur and pre-Spur formats. And the best part is that they share 100% of the source code. There is no forking! This means that there is no extra work in maintaining both flavors. So, we are not leaving anyone behind. It also means that, at deployment, you might chose between better performance and larger memory (with Spur) or smaller footprint and SqueakJS compatibility (with pre-Spur). I've just updated our GitHub repo https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev . Included are Cuis4.2-2906-spur.image and Cuis4.2-2906.image, and, as usual, the whole update stream. I wrote a brief description of the Spur conversion at Documentation/SpurConversion.md, in case you want to reproduce it, or apply it to your own Cuis images. The images seem very stable. Please test them, load your code, and report any issues. This work was enabled by Eliot Miranda and the OpenSmalltalk team who develop Spur, VMMaker and the Spur bootstrap. Thank you folks! I also used Squeak 5 as a reference implementation of Compiler and related stuff. I also want to thank the greater Squeak community for it. Some cleanup is in order. The scaffolding I did for the conversion, including dual Compilers is still in the image. I'll be cleaning it soon. I'll also be able to pay a bit more attention to unrelated suggestions and ongoing discussion at cuis-dev@cuis-smalltalk.org Enjoy! Cheers, Juan Vuletich www.cuis-smalltalk.org https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev @JuanVuletich