Developer

A developer can be one of:

A software developer, one who programs computers or designs the system to match the requirements of a systems analyst.
A real estate developer, one who builds on land or changes and enhances the use of an existing building for some new purpose or to better effect.
Photographic developer is a chemical, often a mixture of metol and hydroquinone, which converts the latent silver halide image in the exposed photograph material into reduced, opaque, black silver metal.