Recently Dan Weinreb mentioned a paper about ObjectStore he co-authored with Charles Lamb, Gordon Landis and Jack Orenstein in 1991. It's a bit hard to find unless you have an ACM account. I've made it available here. Enjoy!

After reading Dan Weinreb's posting I ordered three OLPC XO notebooks. I've met Walter Bender some years ago through a licensing deal with MIT Media Lab. He is now heading the OLPC initiative. This is quite likely the most significant project since Tim Berners Lee's invention of the WWW.

Some nice features of the XO-1:

• Comes with source code for all applications and most of the operating system. There's even a View Source button on the keyboard that shows the code of what's running.
• Based on Linux, but application code is in Python
• 1200x900 7.5" diagonal LCD that works without backlight in bright daylight
• Wireless networking capable of mesh mode
• 2- or 5-cell LiFePO4 battery pack
• Built in color camera

Links:

• Review of the XO-1 by a 12 year old blogger
• Great technical info in the video of the talk at Google by Ivan Krstic, who is the architect of Bitfrost but talks about all aspects of the system

Coming back to a posting from 2004, I'm happy to report that fiction is now science. The Science Blog has an article on the first official use of MRI to "investigate the potential innocence of a woman convicted of poisoning a child in her care."

Link to the source article in European Psychiatry.

During lunch Paul Dale and I talked about self modifying code and how it might apply to real world systems. Later that same day I did a quick check on Wikipedia to read up on the current state of the art. I was surprised to find a link to a paper about self modifying kernel code by Henry Massalin. Reading his PhD thesis about the Synthesis kernel, like learning Lisp, is a mind altering experience. This guy is a genius! My first thought after reading the introduction was: This has to be added to the Movitz kernel!

The Synthesis paper lists four new ideas:

• Run-time code synthesis — a systematic way of creating executable machine code at runtime to optimize frequently-used kernel routines — queues, buffers, context switchers, interrupt handlers, and system call dispatchers — for specific situations, greatly reducing their execution time.
• Fine-grained scheduling — a new process-scheduling technique based on the idea of feedback that performs frequent scheduling actions and policy adjustments (at sub-millisecond intervals) resulting in an adaptive, self-tuning system that can support real-time data streams.
• Lock-free optimistic synchronization is shown to be a practical, efficient alternative to lock-based synchronization methods for the implementation of multiprocessor operating system kernels.
• An extensible kernel design that provides for simple expansion to support new kernel services and hardware devices while allowing a tight coupling between the kernel and the application, blurring the distinction between user and kernel services.

I was curious what a guy like Henry had been doing since finishing his PhD in 1992. Some googling showed that he's working for MicroUnity, a startup that somehow never got any serious traction, filing one patent after another. He is famous for giving people piggyback rides (the inventors of UNIX among them) and he is now known as Ms. Alexia Massalin. Talk about self modification!

Links:

• Synthesis: An Efficient Implementation of Fundamental Operating System Services, Henry Massalin's PhD thesis
• Synthesis, original location of the same paper as Postscript
• Movitz: a Common Lisp x86 development platform, a project started by Frode Vatvedt Fjeld
• Qua, a WIRED article about Henry Massalin
• Superoptimizer: a look at the smallest program by Henry Massalin
• MicroUnity homepage, Alexia Massalin's current employer
• In the Land of the Weird, Standing Out Takes a Little Work, NYTimes article about Dean Dierschow and Alexia Massalin

Marc Andreessen writes about the three different levels of web platforms in this recent blog posting.

I'd like to point out that, as far as I know, Viaweb, an online shop system build by Paul Graham and Robert Morris, was the first level 3 web platform according to the definition given by Andreessen:

A Level 3 platform's apps run inside the platform itself -- the platform provides the "runtime environment" within which the app's code runs.

When one of the customer support people came to me with a report of a bug in the editor, I would load the code into the Lisp interpreter and log into the user's account. If I was able to reproduce the bug I'd get an actual break loop, telling me exactly what was going wrong. Often I could fix the code and release a fix right away. And when I say right away, I mean while the user was still on the phone.

Such fast turnaround on bug fixes put us into an impossibly tempting position. If we could catch and fix a bug while the user was still on the phone, it was very tempting for us to give the user the impression that they were imagining it. And so we sometimes (to their delight) had the customer support people tell the user to just try logging in again and see if they still had the problem. And of course when the user logged back in they'd get the newly released version of the software with the bug fixed, and everything would work fine. I realize this was a bit sneaky of us, but it was also a lot of fun.

Links:

• Beating the Averages by Paul Graham
• The Other Road Ahead by Paul Graham
• Lisp in Web-Based Applications by Paul Graham

For about a year now I've been working for a company in the FX market. As a newcomer to the financial services industry I had to do some background reading. I enjoyed Emanuel Derman's [1] lucid account of his life as a quant. The rise of algorithmic trading in FX over the last couple of years created a tremendous demand for new and more sophisticated models for all financial markets and products. Cornelius Luca [2] wrote the most comprehensive introduction to FX markets I could find. Though a bit lacking on the theoretical side, it gives a good overview about FX products, trading strategies and market dynamics.

The financial services industry is totally hooked on Java. It's just amazing to me, but Java, the second coming of COBOL, is the ecosystem. Unless you look at financial models, which are still mostly done in C++. Although the amount of daily transactions in the FX market is truly mind-boggling, software practice in the industry is in the same wretched state as everywhere else. This is not necessarily a reflection of the intelligence and dedication of the people involved, but when it comes to software, even in high-stakes environments, people work with tools and in a state of mind similar to the Dark Ages. Amazing.

References:

• [1] My Life as a Quant: Reflections on Physics and Finance by Emmanuel Derman
• [2] Trading in the Global Currency Markets, 3rd Edition by Cornelius Luca

I've been doing some research into trust metrics and reputation markets. Electronic markets need a way to create trust between market participants. Of course, as John R. Allen pointed out in his keynote alt ILC05, we need to fix the way we build software first. No cryptographic algorithm will save you, if an attacker can just subvert your platform. First you have to design a trust metric, prove it's correctness, implement it, prove the correctness of the implementation and then you might be able to create reputations and maybe reputation markets. Reputations should be transferable between markets and maybe even tradeable (Charles Stross mentions reputation futures).

Links:

• Capabilities and smart contracts: E-lang
• First Monday: Trust in electronic markets
• Ludwig von Mises Institute: Can the Future Do Without Economic Logic?
• Trust Metric Wiki
• Advogato's trust metric
• Peter Thiel on Virtual Money
• The Economics of Network Industries by Oz Shy
• International Lisp 2005 Conference Keynote by John R. Allen: More Ballast
• GPG and the Web of Trust
• The Global Internet Trust Register: 1999 edition