well today is a very special day in the RS2 World, we have a release.
The Map Development Kit:
Contained within its digital walls are many wonders, including scenery parts, static meshes, and example maps that show how the various map entities work in order to get your very own Thunderhawk or Harpy cruising over the rooftops to a landing zone.
Although playable in deathmatch, its current form should be considered a development tool and NOT a playable mod as it has had most of the major content removed to act as a base from which to create your player maps.
So download and see a little of what we have been up to.
ex_mdk.exe (53,223 KB) OR
ex_mdk.zip (54,183 KB)
For information on how to map with it:
Mapping Documentation