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16.7 Emacspeak And The Early Days Of The Web

Right around the time that I was writing version 0.01 of emacspeak, a far more significant software movement was under way — the World Wide Web was moving from the realms of academia to the mainstream world with the launch of NCSA Mosaic — and in late 1994 by the first commercial Web browser in Netscape Navigator. Emacs had always enabled integrated access to FTP archives via package ange-ftp; in late 1993, William Perry released Emacs-W3, a Web browser for Emacs written entirely in Emacs Lisp. W3 was one of the first large packages to be speech-enabled by Emacspeak — later it was the browser on which I implemented the first draft of the Aural CSS specification. Emacs-W3 enabled many early innovations in the context of providing non-visual access to Web content, including audio formatting and structured content navigation; in summer of 1995, Dave Raggett and I outlined a few extensions to HTML Forms, including the label element as a means of associating metadata with interactive form controls in HTML, and many of these ideas were prototyped in Emacs-W3 at the time. Over the years, Emacs-W3 fell behind the times — especially as the Web moved away from cleanly structured HTML to a massive soup of unmatched tags. This made parsing and error-correcting badly-formed HTML markup expensive to do in Emacs-Lisp — and performance suffered. To add to this, mainstream users moved away because Emacs’ rendering engine at the time was not rich enough to provide the type of visual renderings that users had come to expect. The advent of DHTML, and JavaScript based Web Applications finally killed off Emacs-W3 as far as most Emacs users were concerned.

But Emacs-W3 went through a revival on the emacspeak audio desktop in late 1999 with the arrival of XSLT, and Daniel Veillard’s excellent implementation via the libxml2 and libxslt packages. With these in hand, Emacspeak was able to hand-off the bulk of HTML error correction to the xsltproc tool. The lack of visual fidelity didn’t matter much for an eyes-free environment; so Emacs-W3 continued to be a useful tool for consuming large amounts of Web content that did not require JavaScript support.

During the last 24 months, libxml2 has been built into Emacs; this means that you can now parse arbitrary HTML as found in the wild without incurring a performance hit. This functionality was leveraged first by package shr (Simple HTML Renderer) within the gnus package for rendering HTML email. Later, the author of gnus and shr created a new light-weight HTML viewer called eww that is now part of Emacs 24. With improved support for variable pitch fonts and image embedding, Emacs is once again able to provide visual renderings for a large proportion of text-heavy Web content where it becomes useful for mainstream Emacs users to view at least some Web content within Emacs; during the last year, I have added support within emacspeak to extend package eww with support for DOM filtering and quick content navigation.

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