Archive for March 18, 2014

Tuesday, March 18, 2014 [Tweets] [Favorites]

Leslie Lamport Wins Turing Award


For fundamental contributions to the theory and practice of distributed and concurrent systems, notably the invention of concepts such as causality and logical clocks, safety and liveness, replicated state machines, and sequential consistency.

James Temple:

Among Lamport’s many contributions, one of the most widely implemented is known as the Paxos algorithm, which can be found at work behind the scene in Google or Bing online searches, among much else. It allows a computer network to continue working in a coherent way even in the face of failures, by transferring leadership roles among machines and halting progress rather than allowing damage to occur to the system.

How Was the PDF Format Created?

Alan Tracey Wootton:

John Warnock had the idea that every document that was ever printed, or ever would be printed, could be represented in a document. This was not an unreasonable idea since Postscript was designed for this purpose and Adobe also had some code from Illustrator that would handle the fonts and graphics and code from Photoshop to display images. So, Warnok started a project (the Carousel project) on his own initiative to pursue his idea that eventually the whole Library of Congress could be represented in an archival electronic format.


Peter Hibberd had written a demo of an ‘object oriented file format’ so Richard Cohn and Alan Wootton went to work trying to adapt his work for use on the Carousel project. After many weeks of struggle it was decided that adapting his work was going to be more work than writing new code and that some of the ‘object oriented’ concepts were not applicable since it was finally becoming obvious that a key-value format was going to be part of the solution. This was the third file format.


The name ‘Acrobat’ was created by a market research team from back east.

Leonard Rosenthol:

Concurrent with the release of Adobe Acrobat & Reader 1.0, the specification was published. So while it was proprietary, it was also published and open to all to use (even the patents were made available on a free basis!) This is how open source tools such as Ghostscript and PDFlib have been able to support PDF for most of those 20 years.

John Warnock (PDF):

This document describes the base technology and ideas behind the project named “Camelot.” This project’s goal is to solve a fundamental problem that confronts today’s companies. The problem is concerned with our ability to communicate visual material between different computer applications and systems. The specific problem is that most programs print to a wide range of printers, but there is no universal way to communicate and view this printed information electronically.


In this example the new redefined “moveto” and “lineto” definitions don’t build a path. Instead they write out the coordinates they have been given and then write out the names of their own operations. The resulting file that is written by these new definitions draws the same polygon as the original file but only uses the “moveto” and “lineto” operators. Here, the execution of the PostScript file has allowed a derivative file to be generated. In some sense this derivative file is simpler and uses fewer operators than the original PostScript file but has the same net effect. We will call this operation of processing one PostScript file into another form of PostScript file “rebinding.”

And, speaking of file format longevity, Kendall Whitehouse writes:

From its inception, PDF was, at least in part, a self-describing format. It specifies the filters used to encode its own data stream and, from the outset, Adobe’s Acrobat viewers were designed to interpret a PDF file through these filters. By changing the filter used to decode its own data, Acrobat was able to switch from a pure ASCII file to binary-encoded format. Acrobat Reader 1.0 could read the binary files created by the forthcoming Acrobat 2.0 products.

Jim King:

I have written a paper attempting to describe how Adobe managed the evolution of the PDF file format for over 15 years before turning its management over to ISO. […] This paper was derived from an internal Adobe technical note written by me and a task force of employees who studied the whole issue of versions and compatibility in 2006.

OS X Dictation Alternatives

Nicholas Riley:

OS X Mavericks (10.9) introduces “Enhanced Dictation”, a locally hosted, non-trainable version of Nuance’s recognizer.


Enhanced Dictation’s omissions of training and editing likely protect sales of the Dragon Mac products (discussed below).


Nuance’s Windows dictation products (Dragon NaturallySpeaking and Medical/Legal) are better than their Mac equivalents, though that’s not saying a lot. The UI is a scattered, slowly-evolving mess; true interaction between keyboard/mouse and voice editing is limited to individual versions of specific applications, and the medical product is expensive (upgrades are $500 on sale).

The main reason I dictate into Windows is the ecosystem surrounding the Dragon products there. There are quite a few abandoned research projects and other near-abandonware to contend with, but it’s possible with some effort to construct a productive system.

Nicholas Riley:

I do my serious dictation in a Windows 7 virtual machine. Having recently upgraded my dictation setup and transferred it to a new Mac, I figured it’d be a good thing to share.


Most of the time I’m not actually editing documents directly on Windows; the OS simply holds my text on the way to its destination in a Mac application.

Update (2014-04-15): Nicholas Riley:

Thanks to PowerScribe, I realized that it’s actually easier for me to work with shorter fragments of text, a sentence or a paragraph at a time, rather than importing the entire document at a time. What I’ve implemented so far is on GitHub; here’s a video showing it in use and explaining some technical details.

This Presentation Can’t Be Opened Because It’s Too Old

Stefan Urbanek:

I was greeted with this message today when I was about to publish few more presentations on Slideshare about Knowledge Management. The offending presentation is from 2008. I have around 20 files created in older Keynote versions. They are not the disposable kinds of presentations – you know, the ones that you prepare, project and forget about them. I like to reuse them, show when I’m talking about various subjects contained in them.

How I am supposed to access them now? “save it with Keynote ’09 first”, but how? I don’t have Keynote ’09 any more on my fresh Mavericks install.

And, of course, Keynote ’09 will at some point stop working on new Macs. Apple—and, to a lesser extent, other developers such as Microsoft—cannot be relied upon to support old file formats. The responsibility then falls to the user. If you use an app that creates files in a proprietary format, as soon as a new version comes out you should update all of your documents to the new format. It’s not fun to do this, but there will probably never be an easier time. And it may be a lossy process, so you should also keep the versions in the older format.

Update (2014-03-20): Drew Crawford:

If you are arguing that Apple “should have” implemented this feature, you are also arguing that there are people who want to buy it, and that is a point that is fairly easy to prove.

I do not find this to be a convincing argument. It reminds me of the old joke about how an economist won’t pick up a coin on the ground because, if it were real, someone else would have already found it.

Update (2014-04-14): Thomas Brand:

Even after iWork became a thing, I still find it hard to believe Apple is using its office suite for anything but presentations. Keynote ’09 will stop working on new Macs eventually, and it is hard to ask a company as large as Apple to update every file in its record of knowledge every couple of years.

Update (2014-11-24): The lack of file format compatibility is discussed in Accidental Tech Podcast #90.

Syncing Podcasts: iPhone, Mac, iPod nano

Dr. Drang:

Apple’s Podcasts app promises to handle all the subscription, episode, and playback syncing. The problem, of course, is that Podcasts has always been widely regarded as a piece of shit. But it’s been updated since I first looked at it, and since I second looked at it, too. So I promised myself I’d give Podcasts another tryout, because the upside of automatic syncing on both devices is worth a lesser experience on the phone.

It didn’t work out the way he hoped. I don’t know of a good solution.