Once you sign up for an account, a new Transcribe tab will appear above each page.
You can create or edit transcriptions by modifying the text entry field and saving. Each modification is stored as a separate version of the page, so that it should be easy to revert to older versions if necessary.
Registered users can also add notes to pages to comment on difficult words, suggest readings, or discuss the texts.
Encoding mathematical and scientific formula with LaTex