The typography is off. The body text is written in Arial, which is not a great choice for body text (it's better for display). When in doubt, use Verdana (sans-serif) or Georgia (serif) for body text. Also, the font size is too small.

Here is an example of his blog with better typography. I used 18px Georgia as the body text instead of 12px Arial. I used Droid Sans (a nice display font) for the blog title.

http://i.imgur.com/jhjJA.png

I was under the impression that serif fonts were best left to headlines that are supposed to catch your attention, and that body text should always be a serif font - and that Arial is one of the better serif fonts if you use set the size to at least 14px and line-height to 150%.

You've got a lot of latitude when choosing a font for headlines. Both serif and sans serif work and you can get away with a fonts that have more "personality" than readability.

Body text, however, should be optimized for readability so your choices are more constrained. I don't think there is a huge difference in readability for serif vs. sans serif fonts for body copy. Ask a couple of designers and you'll get a couple of different opinions. Some will say that serif fonts are better because the serifs "lead the eye along". I'm not sure I buy that, but I do prefer serif fonts for body copy. But if you use a serif font, make sure it is big enough. At small sizes the serifs don't render well and get in the way of readability.

I've heard that Arial works better as a display font instead of a font for extended reading, which I tend to believe since it looks so much like Helvetica. If I choose a sans serif font for body copy, I choose Verdana which was specifically designed for the screen. But really, I don't think Arial is necessarily a bad font for body copy. I don't have any objective reason to say why you shouldn't use Arial.

Also, the header font and the body font should contrast, so if you have a serif header font it's usually good to have a sans serif body font and vice versa.

You are missing the word "sans" from that comment.

The general opinion used to be that serif was better for bodytext, and sans for title, and Arial is sans serif, but not one of the better ones.

Yeah, I meant sans serif for body text :)

I find your sample harder to read. Reading the current line I easily get distracted by the next, either because it's too close or too bold.

Thing is it's mostly subjective, so YMMV.

Are the current typography settings better?

http://jacquesmattheij.com/The+worst+program+I+ever+worked+o...

In FireFox, I enable the option View / Zoom / Zoom Text Only.

You should try readability.com

But the fact that readability is suggested, suggests that the site isn't readable. That's a hint to the author that it needs to be looked at, which is what the grandparent comment says.

The author publicly stated he no longer comes to HN, so he won't see any comment here.

I was thinking the exact same thing