List of possible chores

I don't know what the current development status of the website is, but here is a list of things that could be done to bring the website up to date. Most todos are less work than they appear.

• Add missing lang attributes
• Add alternative text to images
• Add <meta name="viewport"> tag
• Remove invalid trailing slashes on void html5 elements
• Remove historic browser fixes for IE
• Remove outdated vendor specific code
• Remove leftovers from outdated services like flattr
• Fix mixed content (gallery)
• Fix broken links
• Fix usage of deprecated js api https://developer.mozilla.org/en-US/docs/Web/API/Navigator/appVersion
• Fix invalid html e.g. <ul> and <ol> must only directly contain <li>, <script> or <template> elements
• Move inline CSS to style file
• Migrate js to ES2015
• Update dependencies
  • jquery to latest v1 (eol) or v3
  • jquery addons
  • font awesome

If you want me to solve some of them please send me feedback.

Start by inventorying the website's HTML, CSS, and JavaScript files against the checklist, since no specific file or entry point is named. Select and scope one chore before making changes; the selected checklist item should be completed and its affected pages verified.