Aprelendo was built using the following free and open source tools:

• PHP, by The PHP Group
• JQuery, by the JQuery Foundation
• Apache, by the Apache Software Foundation
• Bootstrap, by Bootstrap Core Team
• Readability, by Mozilla (used to fetch texts from external web sources)
• DOMPurify, by cure53 (used for security before fetching texts from external web sources)
• Subtitles parser, by Anton Bazhenov.
• EpubJS, by Futurepress (used to render epub files)
• Chart.js, by Chart.js Team (used to render statistics charts)

Other attributions:

• Bootstrap Icons
• Flag icons designed by Freepik
• Frequency lists by Hermit Dave
• Theme based on Solid, by Blacktie
• Wallpaper by JD X from Unsplash