The Development Project is a HL2 modification made out of manipulated Dev textures as a project for those that enjoy the simplicity of the original measuring textures created by valve scattered throughout the map but also enjoy all the effects, adventures and creativity of regular mods.
Very uncommon when it comes to source games these days but this is one thing I have wanted to do for a while that is making glass a bit more interactive yet harder to see through instead of basic flat glass that is quite generic regardless of the texture or tone.