Visi.io is licensed under the MPL 1.1
The code is available on GitHub https://github.com/visi-lang
Patches are gladly accepted, but please ensure that the patches are exclusively your own work, that you grant the patch under the MPL, and that you've updated the Contributors notices in all files that you've patched. Please also include a note with your patch explaining what the patch was, your contact information (e.g., email address), and a message indicating that you are contributing the code under the MPL and that the code is all your own original work.
Right now, Visi.io is very, very raw. It must be compiled using XCode 3.2.5 against GHC-iphone. If this is not your setup, please work on a patch so Visi.io can be compiled and run on a wider variety of Mac setups.