# Appendix - [Tools](https://book.leveldesignbook.com/appendix/tools.md): Links to various level editors, moddable games, engines, and art tools - [TrenchBroom](https://book.leveldesignbook.com/appendix/tools/trenchbroom.md): info and resources for this modern brush-based level editor tool - [Assets & Resources](https://book.leveldesignbook.com/appendix/resources.md): Where to get free art assets (models, textures, materials) for use in levels - [Recommended talks](https://book.leveldesignbook.com/appendix/resources/talks.md): List / archive of level design talks and presentations, with links to videos and slides - [Recommended books](https://book.leveldesignbook.com/appendix/resources/books.md): Recommended level design books... other than this one - [Quake resources](https://book.leveldesignbook.com/appendix/resources/quake.md): Models, textures, sounds, tutorials, and other links for Quake mapping and modding - [How to package a Quake map/mod](https://book.leveldesignbook.com/appendix/resources/quake/how-to-package.md): General rules and guidelines for packaging and publishing playable Quake files - [File formats](https://book.leveldesignbook.com/appendix/resources/formats.md): file formats / specifications for file types used in mapping and modding - [FGD file format](https://book.leveldesignbook.com/appendix/resources/formats/fgd.md): entity definition file / mapping aid for Quake-era level editors - [MAP file format](https://book.leveldesignbook.com/appendix/resources/formats/map.md): file format spec + sample parser code for Quake .MAP files ("Valve" style, mapversion 220) - [MDL file format](https://book.leveldesignbook.com/appendix/resources/formats/mdl.md): how to parse Quake 1 models (.MDL) and sample C source code for rendering in 3D - [Communities](https://book.leveldesignbook.com/appendix/communities.md): links to level design communities, websites, discords, podcasts, blogs, social media - [About this book / authors](https://book.leveldesignbook.com/appendix/about.md): about this book project, its authors, and any credits - [License / copyright](https://book.leveldesignbook.com/appendix/license.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://book.leveldesignbook.com/appendix.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.