From the installation docs
System Requirements
Note: As of 0.1.0-beta.3, Flarum utilizes Composer to manage its dependencies and extensions. This means that Flarum cannot be installed on hosts without SSH (command-line) access. Rest assured that we are planning to address this in the future and make sure that Flarum is accessible to everyone. In the meantime, if you want to run Flarum, you will need to find a host that permits SSH access.
There are a few things that you will need to have set up in order to run Flarum:
- A web server: Apache (with mod_rewrite), Nginx, or Lighttpd
- PHP 5.5+ with the following extensions:
mbstring, pdo_mysql, openssl, json, gd, dom, fileinfo
- MySQL 5.5+
- SSH (command-line) access
I'd also recommend PHP 5.6, as that is what Beta 7 will require.
Check with your host if you're not sure about whether they meet the requirements or not.
