All Sinfar scripting systems are accessible and there's ways (hooks) to modify them without rewriting them.
And much, much more (web client, portraits system, automatic backups, web tools to manage characters…)
Rules
Because of the mature content included in our haks and on some of our documentation pages, all side servers must be rated 18+ (only allow adult players).
Each side servers should be different and provide a new game play style. Try to be unique as much as possible.
There's no limit in terms of “module” size or number of players but the memory and CPU usage of your server process must be acceptable. You don't really have to worry about this point, just don't push it to much by putting 100+ creatures in the same area.
How To
The cost is 20$/month.
You need a team (DMs, area builders and scripters) and a good concept, then when you are ready get started, contact Mavrixio on Discord: https://discord.gg/pM3ja9n