Poster is a unix program that allows one to scale postscript images to a larger size, and print them on larger media and/or tile them to print on multiple sheets.
The program, that has been developed in the 1980ies and has last been updated in 1999, continues to be useful. There are packages available for a number of linux distributions, including Debian and Ubuntu.
While preparing a Formula for the Homebrew package manager for Mac OS X, I found there to be no obvious location to download the source files from. Poster’s author, Jos van Eijndhoven, provided me with a tarball I have put up on Github.
I don’t know C, but I will merge pull requests that keep the program running well contemporary OS’es.