Welcome to the Runtime World Fossil wiki. Runtime World is an open source generic, engine-agnostic, brush-oriented 3D world editor for games written in Lazarus and FreePascal and released under the zlib license (but note a message about my open source projects).
Small update from 2017: while the editor is indeed engine-agnostic and nothing stops you from using it for your own games and engines, it is really being made with Runtime Engine in mind and for the needs of my own projects. Most of the stuff you'll find in this site are from a world where UE4 was still a prohibitively expensive engine, Unity was still something not everyone had their face stuffed with and developers were still interested in the now dying art of homegrown engines made with love and care. Sadly there is no love in this world anymore.
Some (outdated) Wiki pages. Note that except the "Build and Prepare Runtime World" page, the rest probably wont work.