I just refreshed my Slack to current state as usual and after some problems with old HDD (sector errors) I got it working on another, new HDD.

I've been using IBM T23 machine since 4 years, always upgrading to current and I think it wasn't a risky business.
I had no major problems with it as I remember.

Today I discovered small glitch with font rendering in X/Kde.
Lots of fonts are not properly aligned with pixels on my screen resulting in small color fringe at sides of the vertical parts of the fonts. I never saw this before.

Any ideas fellows ?

isn't that sub-pixel hinting?

Yes, I switched off sub-pixel hinting and it's gone. But fonts are not as smooth as always . . .

I guess it's the new freetype. Even before, it has contained some code with patent issues with Apple (the bytecode interpreter), which is not included unless TT_CONFIG_OPTION_BYTECODE_INTERPRETER is defined when compiled. Now the freetype people have noticed that there are some issues with Microsoft patents, too, about sub-pixel rendering. So, that code is now not included unless FT_CONFIG_OPTION_SUBPIXEL_RENDERING in defined. In the previous freetype package in Slackware that macro didn't yet exist, so sub-pixel rendering was always included.