Application for generating 3D structures by specifying a design grammar.
http://structuresynth.sourceforge.net/

F3 [Mac]

Powerful 3D design app that enables you to live code 3D form.
http://www.syedrezaali.com/f3-mac-app/

Fragment [Mac]

App to live code GLSL graphics.
http://www.syedrezaali.com/store/fragment-osx-app

ShaderTool [Win]

Modern shader IDE for programmers and FX artists.
http://store.steampowered.com/app/314720/

Syphon [Mac]

Allows applications to share frames with one another in realtime.
http://syphon.v002.info/

KodeLife

Real-time GPU shader editor, live-code performance tool and graphics prototyping sketchpad.
https://hexler.net/software/kodelife

ISF

GLSL shaders for use in interactive applications.
https://www.interactiveshaderformat.com/