Procedural Generation

Procedural Generation
http://larc.unt.edu/ian/research/content/ 

Procedural Content Generation Wiki
http://pcg.wikidot.com/

Heightmap generator/editor
http://www.ridgenet.net/~jslayton/wilbur.html

Textures
https://github.com/njbrown/texturelab

The Procedurality Engine (Java)
http://oddlabs.com/procedurality.php

http://procworld.blogspot.com/

Voxlap Procedural Caves with Textures
http://moonedit.com/tom/vox1_en.htm

Terrain with Caves:
http://http.developer.nvidia.com/GPUGems3/gpugems3_ch01.html

Lots of Random Generator Tools
http://donjon.bin.sh/

Haxe Markov process name generator:
https://github.com/Tw1ddle/MarkovNameGenerator

SPARTAN Procedural Tile Generator by PNJeffries:
http://pnjeffries.itch.io/spartan-procjam-edition

Procedural Sound Effect
http://drpetter.se/article_sound.html
http://drpetter.se/project_sfxr.html
http://www.bfxr.net/
http://www.superflashbros.net/as3sfxr/

Infinite procedurally generated city with the Wave Function Collapse algorithm
https://marian42.de/article/wfc/

https://voxeltoy.com
https://voxeltoy.com/doc
https://blog.noctua-software.com/goxel-procedural.html

Books:
Texturing and Modeling, Third Edition: A Procedural Approach (The Morgan Kaufmann Series in Computer Graphics)
David S. Ebert (Editor)

http://pcgbook.com/