Martin Geisler Online

I’ve been hosted by NEXCESS for a year now and I must say that it has been an absolutely fantastic experience. The site has been running smoothly without any problems, but what impresses me most is the tech support: every time I’ve contacted them I’ve received a reply from Greg Swaney within five minutes!

Just today I submitted a support ticket, asking them to update the list of IP addresses allowed to SSH into mgeisler.net. I submitted it at 01:58 PM and at 02:03 PM the address was updated and I can now login again. At this speed email tech support is just as good as calling them on the phone, it is much more like chatting than doing email. Very cool, I would definitely recommend NEXCESS to anybody who are looking for a webhost.

Hurray for the Internet! I’ve managed to bring my computer back online after roughly a months break. My new connection is a 2 Mbit StofaNet connection — a nice upgrade from the 768 Kbit connection we had in Switzerland and I’m happily using it for installing my [Debian][] system!

It’s nice finally to have my computer online again — I can check and answer mail using the web-interfaces, but I somehow don’t get that much work done without my own computer. I hope that will change now ;-)

After some succesful lobbing by Thomas, Rune decided to start a blog (just writing “Rune” should be unambigious now that the other Rune has changed name to Evil Princess kirkebrand…). So he is now a (proud?) member of Planet DAIMI as well.

I also found and added Dan’s blog. If you guys know of any other blogs you want added, then send me a mail.

It’s a common misunderstanding that when you typeset something with [LaTeX][], then you have to use the Computer Modern typeface, a beautiful font covering tons of characters designed by Donald E. Knuth.

Okay, that’s probably not entirely true — you might know that \usepackage{pxfonts} will give you Palatino (Garamond) instead, or that \usepackage{times} does the same for the insanely popular Times New Roman.

But did you know that there’s many more available? Palle Jørgensen from the Danish TeX User Group has made a cool site called the LaTeX Font Catalogue where you can check no less than 94 freely available fonts for use with TeX and LaTeX!

A whopping 21 comes with support for typesetting math. Most fonts simply have the characters needed to typeset letters and numbers plus the common pecial characters, but some fonts also have the glyphs needed for stuff line integrals, arrows, greek letters, etc. Using two different fonts (one for the body text and one for the math) is normally a bad idea because the fonts might have different weights (different blackness) and different height. Still, people often mix, say, Helvetica (a sans serif font!) with Computer Modern (a very “seriffed” font!)… it do that, it looks icky.

Here’s an example of some math typesat with a font called Kurier Light Condensed:

Even though I’ve used LaTeX for years now, and I’ve been interested in typography for some time, I was surpriced to see so many free fonts available for LaTeX. The problem is actually not the availability of fonts — I guess that most of us have a couple of hundred TrueType fonts on some CD somewhere, and TrueType fonts can be used with a modern version of (pdf)LaTeX. The problem is just that using an arbitrary TrueType font involves some converting and some configuring — it needs the right infrastructure.

But for those 94 fonts this has already been done by the nice people who make the TeX Live LaTeX distribution. I’m currently using the default LaTeX that comes with [Debian][], namely teTeX and it has always worked great for me. But now I’m looking forward to seeing TeX Live in Debian — the packages have now entered experimental, and that’s an important step on the way to be included with Etch, the next stable version of Debian.

Before I created the planet (what a funny thing to write :-) I never looked at my RSS feeds, but now they’ve suddenly become very important. And they’re wrong! Or rather, the Etag and Last-Modified headers sent out are false, and so browser and feed aggregators wont be updated as they should.

Take a look at this trace caught with the excellent Live HTTP Headers plugin for Firefox — I’ve removed most of the other headers except for the Etag and Last-Modified headers. First I request Rune’s RSS feed for comments using Shift-”reload” to make Firefox bypass its own cache:

GET /?feed=comments-rss2 HTTP/1.1
Host: kirkebrand.dk
Pragma: no-cache
Cache-Control: no-cache

HTTP/1.x 200 OK
Date: Wed, 25 Jan 2006 21:12:50 GMT
Last-Modified: Wed, 25 Jan 2006 09:14:20 GMT
Etag: "0dfff2fe5ab59c79c6105ac336b388ed"
Status: 200 OK

Bravo! We get the feed back.

I then posted a comment, which should update the feed. Reloading in Firefox looks like this where it does a conditional HTTP request by sending the Etag and Last-Modified headers along:

GET /?feed=comments-rss2 HTTP/1.1
Host: kirkebrand.dk
If-Modified-Since: Wed, 25 Jan 2006 09:14:20 GMT
If-None-Match: "0dfff2fe5ab59c79c6105ac336b388ed"
Cache-Control: max-age=0

HTTP/1.x 304 Not Modified
Date: Wed, 25 Jan 2006 21:13:54 GMT
Last-Modified: Wed, 25 Jan 2006 09:14:20 GMT
Etag: "0dfff2fe5ab59c79c6105ac336b388ed"
Status: 304 Not Modified

Hmm… that shouldn’t have been a 304 Not Modified, but a 200 OK with a new Last-Modified header and a new Etag! The funny thing is that when I press Shift and reload the page I and get the updated feed, but the headers still look like this:

http://kirkebrand.dk/?feed=comments-rss2

GET /?feed=comments-rss2 HTTP/1.1
Host: kirkebrand.dk
Pragma: no-cache
Cache-Control: no-cache

HTTP/1.x 200 OK
Date: Wed, 25 Jan 2006 21:14:08 GMT
Last-Modified: Wed, 25 Jan 2006 09:14:20 GMT
Etag: "0dfff2fe5ab59c79c6105ac336b388ed"
Status: 200 OK

So something is definitely wrong here! I would be happy if some of you could try out the procedure above yourself and report your findings. I’ve seen this problem on my own blog and on Lars’ blog too, so the problem seems to affect version 1.5.2 as well as the new 2.0.