The only problem with Postscript in the early days was that it was difficult to view the output unless you had a Postscript printer; they were not universally available.
RALPage was interpreter for PostScript, which ran on several workstations, and produced images of the document on the display. The interpreter implemented the full language, and almost all of the graphics functions. A version was used on many user sites external to RAL.
Black and White laser printers only produced bi-level output, and used half-tone techniques to simulate colours or grey shades. RALPage was implemented on a greyscale display and there was a distributed processor version which permitted the language interpreter to run on a different processor from that driving the display.
Crispin Goswell wrote the interpreter. After the initial release the PostScript interpreter was improved including non-integer scaling, arbitrary rotation of bitmaps, the setscreen function, fast area fill and complex clipping. Optimised text printing was also provided - this gave a speed up of about four times. Ports were done to Whitechapel, Orion, Vax and Pyramid (these last two permitted remote viewing). By November 1987 the software was posted to the Usenet news network and was in use at many hundreds of sites world-wide. The software was later improved to read screen fonts in preference to the previous algorithmically generated ones. Some productising was done to make it part of the Informatics Unix Service.
