I've been writing a lot about self-driving cars which have automatic accident avoidance and how they will change our cities. I was recently talking again with Robin Chase, whose new company, goloco attempts to set people up for ad-hoc carpools and got into the issues again. She believes we should use more transit in cities and there's a lot of merit to that case.

However, in the wealthy USA, we don't, outside of New York City. We love our cars, and we can afford their much higher cost, so they still dominate, and even in New York many people of means rely strictly on taxis and car services.

Transit is, at first glance, more energy efficient. When it shares right of way with cars it reduces congestion. Private right of way transit also reduces congestion but only when you don't consider the cost of the private right-of-way, where the balance is harder to decide. (The land only has a many-person vehicle on it a small fraction of the time compared to 1-3 passenger vehicles almost all the time on ordinary roads.)

However, my new realization is that transit may not be as energy efficient as we hope. During rush hour, packed transit vehicles are very efficient, especially if they have regenerative braking. But outside those hours it can be quite wasteful to have a large bus or train with minimal ridership. However, in order to give transit users flexibility, good service outside of rush-hour is important.

As part of my series on the horrors of modern system administration and upgrading, let me propose the need for a universal API, over all operating systems, for accessing data from, and some control of the package management system.

There have been many efforts in the past to standardize programming APIs within all the unix-like operating systems, some of them extending into MS Windows, such as Posix. Posix is a bit small to write very complex programs fully portably but it's a start. Any such API can make your portability easier if it can't make it trivial the way it's supposed to.

But there has been little effort to standardize the next level, machine administration and configuration. Today a large part of that is done with the package manager. Indeed, the package manager is the soul (and curse) of most major OS distributions. One of the biggest answers to "what's the difference between debian and Fedora" is "dpkg and apt, vs. rpm and yum." (Yes you can, and I do, use apt with rpm.)

Now the truth is that from a user perspective, these package managers don't actually look very different. They all install and remove packages by name, perform upgrades, handle dependencies etc. Add-ons like apt and GUI package managers help users search and auto-install all dependencies. To the user, the most common requests are to find and install a package, and to upgrade it or the system.

An eBay reputation is important if you're going to sell there. Research shows it adds a decent amount to the price, and it's very difficult to sell at all with just a few feedbacks. Usually sellers will buy a few items first to get a decent feedback -- sometimes even scam items sold just for feedback. Because savvy buyers insist on selling feedback, it's harder, and sometimes sellers will also sell bogus items just for feedback as a seller. eBay has considered offering a feedback score based on the dollar volume of positive and negative transactions but has not yet done this.

The use of virtual machines is getting very popular in the web hosting world. Particularly exciting to many people is Amazon.com's EC2 -- which means Elastic Compute Cloud. It's a large pool of virtual machines that you can rent by the hour. I know people planning on basing whole companies on this system, because they can build an application that scales up by adding more virtual machines on demand. It's decently priced and a lot cheaper than building it yourself in most cases.

In many ways, something like EC2 would be great for all those web sites which deal with the "slashdot" effect. I hope to see web hosters, servers and web applications just naturally allow scaling through the addition of extra machines. This typically means either some round-robin-DNS, or a master server that does redirects to a pool of servers, or a master cache that processes the data from a pool of servers, or a few other methods. Dealing with persistent state that can't be kept in cookies requires a shared database among all the servers, which may make the database the limiting factor. Rumours suggest Amazon will release an SQL interface to their internal storage system which presumably is highly scalable, solving that problem.

As noted, this would be great for small to medium web sites. They can mostly run on a single server, but if they ever see a giant burst of traffic, for example by being linked to from a highly popular site, they can in minutes bring up extra servers to share the load. I've suggested this approach for the Battlestar Galactica Wiki I've been using -- normally their load is modest, but while the show is on, each week, predictably, they get such a huge load of traffic when the show actually airs that they have to lock the wiki down. They have tried to solve this the old fashioned way -- buying bigger servers -- but that's a waste when they really just need one day a week, 22 weeks a year, of high capacity.

However, I digress. What I really want to talk about is using such systems to get access to all sorts of platforms. As I've noted before, linux is a huge mishmash of platforms. There are many revisions of Ubuntu, Fedora, SuSE, Debian, Gentoo and many others out there. Not just the current release, but all the past releases, in both stable, testing and unstable branches. On top of that there are many versions of the BSD variants.