This release features a complete JavaScript back-end, which replaces the previous prototypes. Use it with --target=js. At the moment it’s not that useful, as you can’t use it to make standalone programs, but that will come, along with the ability to use the built-in sourcemap support in IDEs. It should provide a handy speed-up as well.
return can now only be used at the top level of blocks. You can no longer write a horror such as 1 + return 2, though if you must, you can simply use a parenthesized block.
The URSA_HISTORY environment variable can now be used to point to a user-defined history file.