Naven
Glossary
Screen reader
Software that reads a screen aloud for people who cannot see it.
VoiceOver, NVDA, JAWS and TalkBack turn a page into speech, navigating by heading, link and control. What they read is the accessibility tree the browser builds from the markup — which is why a button made from a div announces nothing useful, however it looks.
Good markup is most of accessibility. A heading that is a heading and a button that is a button costs nothing and does most of the work.
Where Naven stands
Naven's chrome is built from real buttons and headings with labels, so the structure a screen reader reads matches the one a sighted person sees.