A lot of people have also used Adobe PageMaker, Microsoft PowerPoint and Adobe Photoshop. Technically, if you can print to a file from the program, you can create a postscript file to upload to the plotters. Vector formats are the easiest and cleanest images for enlarging. However, raster images are a collection of colored pixels that can not, by themselves, be enlarged. One method for enlarging these pixels is to create a larger square and fill it.
Some software packages expand the dithering area for that pixel.
Either way your enlarged image will pixelate. There are several packages available that will allow you to mix both vector and raster formats. Some examples would be Illustrator, Canvas or CorelDraw. There are many other programs as well. When the plotter receives a data file that is a mixture of vector and raster images, it must first rasterize the entire file.