We are delighted to announce GNU Guile 2.2.1, the first bug-fix release in the new 2.2 stable release series. This release adds a "sandbox" facility that can run code from untrusted users. It also includes a compiler and runtime change that ensures that attempts to mutate literal constants will always throw an exception. Before this change, the mutation would either succeed, potentially corrupting further use of that constant or other constants sharing structure with it, or cause a segmentation fault if that data happened to be mapped read-only.
See the release announcement for full details and a download link.