The following new entries were just added to the table at
https://registry.scheme.org/#version-properties.

(Since SRFI 176 is final, the SRFI document won't be updated to reflect
the changes.)

These properties debuted in STklos.

c.library.compile    Command to compile C shared library to be loaded by
the implementation
c.library.extension    File name extension (with dot, e.g. ".so" or
".dylib") for shared libraries to be loaded by the implementation
c.library.link    Command to link C shared library to be loaded by the
implementation

scheme.srfi.count    How many SRFIs are known to be supported

threads    Which backends can be used for multithreading on this system?
Known values: pthreads, win32