It not patents now. The biggest barrier isplexity. And market forces of an installed base. PDF files are apressed version of a language derived from the PostScript s language which itself must have apiler existing to translate into the platform native vector graphics API. Whenever you display orpose or read a PDF file you are drilling down to Postscript layer and changing Postscript programming code italic and then packing it all back up into the neat little package with bow italic we call PDF. Here an example of Postscript code from the wiki page %!PS code % name the desired font code 2 selectfont % choose the size in points and establish code % the font as the current one code 72 5 moveto % position the current point at code % coordinates 72 5 (the origin is at the code % lower-left corner of the page) code (Hello world!) show % stroke the in parentheses code showpage % print all on the page code This pile ofplexity is FAR BEYOND your average Brogrammer to code. Then you look at the breadth and depth of the installed base of Adobe PDF and of MacOS Adobe has successfully made PDF the lingua franca of all printing and publication workflows in the world and they have tools for that entire process chain that work really well. So going up against Adobe is a bit naive and ambitious. MacOS iOS and iPadOS vector graphics API is based on a derivative of Postscript called Display Postscript implemented as the Apple Quartz API - so it eliminated several layers of the above stack on those platforms. This is why youve always been able to Print to PDF on Mac OS X in EVERY application that supports printing what you see on the screen is Postscript-ready and thus PDF-ready by design. Quartz | Apple Developer Documentation s On Windows Linux or Web apps you still have to manipulate the entire stack. Just to read write and modify PDF files. You be prepared to write a Postscriptpiler and code that can manipulate graphics by changing postscript code and then apiler target intermediate language that can call the local vector graphics API of the platform you are targeting. Or you have to pay for a library someone has written to do the same. For which you may or may not have to pay additional royalties for each copy you sell or distribute. That in incentive to write your own if you can but most can not. At that point on Windows and linux you arepeting with people who have already used the same available libraries which are already implementing most of what you could ever offer as apetitive advantage in your own product. All those PDF Editor programs and web sites you see advertised online for editing PDF files. Most of thepetitive advantage beyond these programs requires digging into the Postscript level of code. On Apple products you can equivalently do that using the Quartz and Cocoa APIs which directly generate Display Postscript and thus always generate error-free Postscript and PDF. So it super easy and part of why graphics is still often done on these platforms. You can buy apps for Windows such as Adobe. Since you can get the entire Adobe Creative Cloud s for $54 which covers all publishing workflows that bes your primarypetitive barrier and price point. Adobe has this entire stack codebase designed and debugged. You be starting from scratch to do something similar. Now estimate how much you need to hire for programming talent and how many copies you need to sell and how soon you are likely to gain market share to do that. and that leads you to some other more profitable project pretty quick.