Unfortunately I didn't get that many questions in, there were so many people spamming him.
I asked him some other questions in chat, he told me that titles are handled with an enumeration, I asked him why they didn't use an array and he didn't answer.
It says on RS Wiki that "runescript", the language JAGEX uses to create content for RuneScape.
We can learn this from the RS Wiki.
"RuneScript is a scripting language that Jagex uses to create content for RuneScape. The game engine is not written in RuneScript, but instead Java. RuneScript was developed by Jagex Ltd. to allow their other staff that do not know Java to add and edit content for the game. The game engine reads RuneScript files and executes them accordingly. This is the structure most larger programs (such as other video games) follow." ~ RS Wiki.
We write in a scripting language called RuneScript, which our Game Engine team has created specifically for making RuneScape content. The Java-based game engine then reads this RuneScript code and makes it all work. RuneScript is constantly being changed and expanded as we add new features to it to allow it to do new things." — Mod John A New Dwarf Quest: Coding and Writing
Hmm, syntax wise it's similar to any C-style language, except variable names are prefixed with their type (eg. %varname is an integer). We also lack full array support. Other than that, it'd do pretty much anything you could do in C or Java. — Mod Chris E Game Engine Q&A
The minor updates are usually for introducing a new map and adding new NPCs, and for these updates, a RuneScript file is added into the program. The major updates are for the source code, which is usually for making large changes such as introducing new areas in RuneScape, new skills, or for bug fixes.
Here is a Code sample of RuneScript that most of you interested in this would have seen.