When — mostly programmers, in fact — refer to the Netpbm format they usually imply a group of filename extensions associated with graphic images, including the following:
- PPM (Portable Pixmap Format), designed to represent full-color images
- PGM (Portable Graymap Format), corresponding to grayscale
- PBM (Portable Bitmap Format), representing black-and-white images
All these 3 image file formats can also be found under a single name: PNM (Portable Anymap Format). All were created in the 1980s and became very popular at the time among programmers and computer engineers. Their main advantage was their “portability” or ability to be easily exchanged on different platforms. The Netpbm package used to be a leading group of software used by designers and programmers to easily handle and edit images. But this was all before programs such as Corel Draw, Adobe Photoshop or Gimp became as widely available as they are today.