PHP 7 compatibility extension for Magento 1 core by Inchoo. Article with some tests and stats: http://inchoo.net/magento/its-alive/.
Tested on M CE 1.9.2.2 - 1.9.2.4 & M EE 1.14.2.2 - 1.14.2.4.
(CE version of extension is in master branch, and EE version is in EE branch.)
Older versions of Magento may work, but may also have other problems, not fixed by this extension.
If you can, upgrade to freshest Magento core first. If you can't, this may be a good starting point to make a branch for older versions.
Backwards compatible with PHP. Tested by us on PHP 5.6 & 5.5. Users have reported it working fine even on 5.3.3. Installing the extension before switching to PHP 7 is a good idea.
Read the Wiki! It contains a lot of great information and stuff you need to do or know about running M1 on PHP7.
May be incompatible with PHP 7. We can't do anything about that. But their authors can.
MIT. (See LICENSE.txt).
Yes. (Of course.) See Issues tab. Issue reporting is welcome. Pull requests are welcome. (But read Wiki and existing code first.)
For Composer install, available on Firegento: http://packages.firegento.com/ . Because of strict Composer versioning rules, only the CE version will show up there versioned. Use dev-EE for Enterprise version. (At least for now.)
Or just download ZIP of the latest release and copy files to appropriate locations.
Remember to clear the cache. Also, check Proper Installation Wiki page.