Yeah I wasn't impressed with the examples either.

Maybe try opening the PDF instead of the PNG, the PNG images of text look off to me as well but the font rendering in the PDF looks fine.

I dunno - that doesn't help anything with the layout. I still see overlapping text, tables with crooked columns, bad spacing between paragraphs and titles. The kerning got better, even though there is still something wrong with the stroke weight of the font. Maybe its just a really bad font, and not something related to Sile. Choosing a bad font to showcase a typesetting system is a bit of a redflag imo.

In case someone is wondering, here’s a table from the doc book example: [0]

FWIW, in FF, Win the PDF fonts have aliasing issues when not zoomed in, Sumatra PDF looks much better.

[0]: https://i.imgur.com/EERxV4W.png

I think the font choice is a lot of it, at least. Sile may be a great typesetting system technically, but the examples kind of look, well, like they were put together by someone who maybe doesn't know much about good layout and typography.

Yes, the typeface is horrible, no question about it, but the other issues mentioned are definitely also there.

I think most of the problem is the font they use

I don't know enough about the system, but good text justification is only the first step in a good document. TeX, through LaTeX and the various report/book/etc environments has centuries of man time dedicated to getting the best possible output for a given document type.