Today, Hypothesis and our partners, NYU Press and NYU Libraries, the Readium Foundation, Evident Point and EPUB.js, are announcing the world’s first open-source, standards-based annotation capability in an EPUB viewer — or rather two EPUB viewers, because we’re launching with identical functionality in the two most popular open-source frameworks, Readium and EPUB.js. For the first time, publishers and others now have a complete annotation solution for all their content published in all three primary digital formats: HTML, PDF and now, EPUB.