Closing a TODO, I've filtered the list of Scheme implementations to find candidates for experimenting with using Scheme as a VM. The winners are:
Now description of the filtering process.
The page http://community.schemewiki.org/?scheme-faq-standards#implementations provides a list of all Scheme implementations. I followed each link to find if a tool is a compiler or an interpreter. I got:
The next filtering step is to search in Google for the phrases "virtual machine site:xxx" and "backend site:xxx", where xxx is the homepage of the tool. If something is found, the tool is retained in the list. Now the list is shorter:
The list is finally small. On the last step, I reviewed the documentation of the tools to find that they really support r5rs and real compilation and that the documentation is helpful for my goals. This way, I've got the 3 winners listed in the beginning.