Here's a small thing that annoys me: Presentations in HTML. It feels almost like a form of DRM! Please release slides in PDF.
First of all, it's trivial to convert HTML to a PDF, just hit Ctrl+P in your browser.
HTML works much better when viewed across multiple screen sizes, and has better accessibility features. If the HTML is well written, it will also be perfectly readable in CLI viewers.
PDF is a much more opaque format.