UPDATE: Editor Source Code (Not included in preview release)
With the 5.4 full release, the Sandbox Editor source code will be provided to users so that they can extend the Sandbox Editor for their own custom tools and applications. In this release, we have taken time to provide the resources and knowledge necessary to work within the Sandbox Editor code and to develop Editor Plugins that are fully integrated with the Sandbox Editor and its most advanced systems.
With the release of the Sandbox Editor source code, we have also planned to expose a new Sandbox Editor programming section within our Technical Documentation. This section would include sample plugins that can be used to access and extend the Sandbox Editor from the base we deliver.
We are looking forward to contributions from the community to strengthen and supplement the tools that are offered with CRYENGINE!