It won't win any practicality, image quality or functionality competition, but it will give second life to a broken monitor and some pipe leftovers from another project.

Can project stuff on other stuff, has plenty of mounting points for accessories, can be oriented upright or horizontally, has somewhat adjustable (focus, throw, vignette) and modular (housings are separable) lens stack and probably will not melt within an hour of operation.

Mostly 3D printable, but some fasteners, electronics and metal structure parts are required.