All browsers: The free JISC TechDis bookmarklet and user script does something long overdue for web users. It creates a toolbar that makes text bigger, changes its font, reads it out loud, spell checks it and even pulls its references.
Crafted by the University of Southampton's electronics and computer science school, the toolbar is offered in one of three ways: as an instant toolbar bookmarklet that can be used on pretty much any browser, a Greasemonkey-style user script that can be installed just as universally and a Windows-only installer that does the installing for you. What the toolbar itself does is provide a whole lot of neat tools — text-to-speech reading, font fixing and magnification, spell checking and reference searching — that exist in a lot of different places in the browser and in other browser add-ons, but make more sense as a click-to-activate toolbar.
Seems like a great tool for students, those who have trouble with the web's standard layouts and anyone looking for an easier go of reading a page. It's a free download for any browser on any OS.
JISC Techdis Toolbar [University of Southampton]