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Linux running inside a PDF file via a RISC-V emulator - ading2210/linuxpdf
The full specfication for the JS in PDFs was only ever implemented by Adobe Acrobat, and it contains some ridiculous things like the ability to do 3D rendering, make HTTP requests, and detect every monitor connected to the user's system. It works by using a separate text field for each row of pixels in the screen, whose contents are set to various ASCII characters. For inputs, there is a virtual keyboard implemented with a bunch of buttons, and a text box you can type in to send keystrokes to the VM.
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