Technology - 8. page

I thought this list of software licensing haikus was pretty funny.

Kinda old, thought I’d update with some other licenses:

Apache: not the GPL! / we let you reuse to sell / you break it you buy
Creative Commons: choose one from many / confused? we will help whether / simple or sample
Berkley: do not remove the / notice, nor may you entangl’ / berkeley in your mess
Artistic: tell all if you change / package any way you like / keep our copyright

As you may have noticed, especially if you use an RSS reader, I’ve installed Yahoo Ads beta program on some of my pages. For the next few months, I plan to run Yahoo Ads on the individual article pages, as well as my popular JAAS tutorial.

I’ve not done anything like this before, but since I write internet software, and pay per click advertising is one of the main ways that such software makes money, I thought it’d be an interesting experiment. Due to the dictatorial Term and Conditions, I probably won’t comment on any other facets of the ads in the future….

Please feel free to comment if you feel that the ads are unspeakably gauche–can’t say I’ve been entirely happy with their targeting.

Most people know about mozilla through Firefox, their IE browser replacement. (Some geeks may remember the Netscape source code release.) But mozilla is a lot more than just a browser–there’s an entire API set, XPCOM and XUL, that you can use to build applications. (There are books about doing so, but mozilla development seems to run ahead of them.) I’m working on a project that needs some custom browser action, so looking at XPCOM seemed a wise idea.

XPCOM components can be written in a variety of languages, but most of the articles out there focus on C++. While I’ve had doubts about scripting languages and large scale systems, some others have had success heading down the javascript path. I have no desire to delve into C++ any more than I have to (I like memory management), so I’ll probably be writing some javascript components. Unfortunately, because XPCOM allows javascript to talk to C++, I won’t be able to entirely avoid the issue of memory management.

xpcshell is an application bundled with mozilla that allows me to interact with mozilla’s platform in a very flexible manner. It’s more than just another javascript shell because it gives me a way to interact with the XPCOM API (examples). To install xpcshell (on Windows) make sure you download and install the zip file, not the Windows Installer. (I tried doing the complete install and the custom install, and couldn’t figure out a way to get the xpcshell executable.)

One cool thing you can do with xpcshell is write command line javascript scripts. Putting this:

var a = "foobar";
print(a);
a=a.substr(1,2);
print(a);

in a file named test.js gives this output:

$ cat test.js | ./xpcshell.exe
foobar
oo

Of course, this code doesn’t do anything with XPCOM–for that, see aforementioned examples.

I did run into some library issues running the above code on linux–I needed to execute it in the directory where xpcshell was installed. On windows that problem doesn’t seem to occur.

A few other interesting links: installing xpcshell for firefox, firefox extensions with the mozilla build system, a javascript library easing XPCOM development, and another XPCOM reference.

Update, 2/9/06: this post only outlines how to set up a geocode engine for the United States. I don’t know how to do it for any other countries.

Geocoder.us provides you with a REST based geocoding service, but their commercial services are not free. Luckily, the data they use is public domain, and there are some helpful perl modules which make setting up your own service a snap. This post steps you through setting up your own geocoding service (for the USA), based on public domain census data. You end up with a Google map of any address in the USA, but of course the lat/long you find could be used with any mapping service.

First, get the data.

$ wget -r -np -w 5 --random-wait ftp://www2.census.gov/geo/tiger/tiger2004se/ 

If you only want the data for one state, put the two digit state code at the end of the ftp:// url above (eg ftp://www2.census.gov/geo/tiger/tiger2004se/CO/ for Colorado’s data).

Second, install the needed perl modules. (I did this on cygwin and linux, and it was a snap both times. See this page for instructions on installing to a nonstandard location with the CPAN module and don’t forget to set your PERL5LIB variable.)

$ perl -MCPAN -e shell
cpan> install S/SD/SDERLE/Geo-Coder-US-1.00.tar.gz
cpan> install S/SM/SMPETERS/Archive-Zip-1.16.tar.gz

Third, import the tiger data (this code comes from the Geo::Coder::US perldoc, and took 4.5 hours to execute on a 2.6ghz pentium4 with 1 gig of memory). Note that if you install via the CPAN module as shown above, the import_tiger_zip.pl file is under ~/.cpan/:

$ find www2.census.gov/geo/tiger/tiger2004se/CO/ -name \*.zip 
  | xargs -n1 perl /path/to/import_tiger_zip.pl geocoder.db

Now you’re ready to find the lat/long of an address. Find one that you’d like to map, like say, the Colorado Dept of Revenue: 1375 Sherman St, Denver, CO.

$ perl -MGeo::Coder::US -e 'Geo::Coder::US->set_db( "geocoder.db" );
my($res) = Geo::Coder::US->geocode("1375 Sherman St, Denver, CO" ); 
print "$res->{lat}, $ res->{long}\n\n";'

39.691702, -104.985361

And then you can map it with Google maps.

Now, why wouldn’t you just use Yahoo!’s service (which provides geocoding and mapping APIs)? Perhaps you like Google’s maps better. Perhaps you don’t want to use a mapping service at all, you just want to find lat/longs without reaching out over the network.

Gervase Markham has written an interesting article about open document formats. I did a bit of lurking on the bugzilla development lists for a while and saw Gervase in action–quite a programmer and also interested in the end user’s experience. I think he raises some important issues–if html had been owned by a company, the internet (as the web is commonly known, even though it’s only a part of the internet) would not be where it is today. If Microsoft Word (or WordPerfect) had opened up their document specification (or worked with other interested parties on a common one), other companies could have competed on features and consumers would have benefited. More on OpenDocument, including a link to a marked up version of a letter from Microsoft regarding the standard.

Seems like the Wikipedia model isn’t for everyone: Congress abandons WikiConstitution.

In the past few months, I’ve become a huge fan of vmware, the Workstation in particular. If you’re not familiar with this program, it provides a virtual machine in which you can host an operating system. If you’re developing on Windows, but targeting linux, you can run an emulated machine and deploy your software to it.

The biggest, benefit, however, occurs when starting a project. I remember at a company I worked at a few years ago, I was often one of the first people on a project. Since our technology stack often changed to meet the clients’ needs, I usually had to learn how to install and troubleshoot a new piece of server software (ATG Dynamo, BEA Weblogic, Expresso, etc). After spending a fair amount of time making sure I knew how to install and deploy the new platform, I then wrote up terse yet complete (hopefully) installation documents for the future members of the team as the project rolled into development. Of course, that was not the end of it; there were slight differences in environment and user capability which meant that I was a resource for the rest of the team regarding platform configuration.

These factors made me a strong proponent of server based development, where you buy a high powered box and everyone develops (via CVS, samba or some other network protocol) and deploys (via a virtual server for each developer) to that box. Of course, setting it up is a hassle, but once it’s done, adding new team members is not too much of a hassle. Compare this with setting up a windows box to do java development, and some of the complications that can ensue due to the differing environments.

But vmware changes the equation. Now, I, or someone like me, can create a development platform from scratch that includes everything from the operating system up. Combined with portable hard drives, which have become absurdly cheap (many gig for a few hundred bucks) you can distribute the platform to a new team member in less than hour. He or she can customize it, but if they ruin the image, it’s easy enough to give the developer another copy. No weird operating system problems and no complicated dev server setup. This software saves hours and hours of development time and lets developers focus on code and not configuration. In addition, you can actually do development on an OS with a panoply of tools (Windows) and at the same time test deployment to a serious server OS (a UNIX of some kind).

However, there are still some issues to be aware of. That lack of knowledge often means that regular programmers can’t help debug complicated deployment issues. Perhaps you believe that they shouldn’t need to, but siloing the knowledge in a few people can lead to issues. If they leave, knowledge is lost, and other team members have no place to start when troubleshooting problems. This is, of course, an issue with or without vmware, but with vmware regular developers really don’t even think about the install process; with an install document, they may not fully understand what they’re doing, but probably have a bit more knowledge regarding deployment issues.

One also needs to be more vigilant than ever about keeping everything in version control; if the vmware platforms diverge, you’re back to troubleshooting different machines. Ideally, everyone should mount a local directory as a network drive in vmware and use their own favorite development tools (Eclipse, netbeans, vi, even [shudder] emacs) on the host. Then each team member can deploy on the image and rest assured that, other than the code or configuration under development, they have the exact same deployment environment as everyone else.

In addition, vmware is a hog. This is to be expected, since it has an entire operating system to support, but I’ve found that for any real development, 1 gig of RAM is the absolute minimum. And if you have more than one image running at the same time, 1 gig is not enough. A fast processor is needed as well.

Still, for getting development off to a galloping start, vmware is a fantastic piece of software. Even with the downsides, it’s worth a look.

About two years ago, I wrote about how to secure your wireless network by changing your router password, your SSID, and turning on WEP. Regarding WEP, I wrote:

This is a 128 bit encryption protocol. It’s not supposed to be very secure, but, as my friend said, it’s like locking your car–a thief can still get in, but it might make it hard enough to not be worth their while.

Now, some folks have created a flash movie showing just how easy it is to break WEP. Interesting to watch, and has a thumping soundtrack to boot.

Via Sex, Drugs, and Unix.

Any new technology needs to fit into existing societal infrastructures, whether it’s the printing press or the closed circuit TV system. Blogging is no different. I sometimes blog about what I get paid to work on, but always check with my employer first to make sure they’re comfortable with it. Since I’m a developer, it’s often general solutions to problems, and if need be, I omit any identifying information. Some folks take it farther..

Now, our good friends at the EFF have produced a legal guide for bloggers, which looks to be very useful, but is aimed only at those who live in the United States of America.