A default font will be set if a language or script has a problematic support history on a wide range of desktop computers and other devices. Even though most modern operating systems provide options to support a language or script well, this may require a user to take action first, such as installing software or changing the operating system settings. Our experience shows that a lot of users don't do this and give up, and we want to provide a quick and automatic way to make the text readable.

Universal Language Selector only provides freely licensed fonts. We choose default fonts based on popularity of the fonts (eg: default font for a script in Linux distributions, widely used in portals in the language, etc.) and based on input from potential users. If the default font has a bug that prevents users from using it, we will try to use an alternate font if available. For this a valid bug report is needed in bugzilla with high impact.

Experienced users that have made all the effort, can easily switch back to using the default font using ULS.

mohahmwiki wrote:

The Amiri font has a problematic support history on all devices, italic and bold fonts are messing. Isn't that enough reason to select another default font? Also, we have made a vote after many, many complains. This vote turned out in favour of disabling the web font extensions or selecting another web font. Again, I point out to the problem of editing long pages that might might be connected to web fonts.

This really a severe issue, and it has been going on long enough.

abanima wrote:

The now-default Amiri font has several disadvantages. When activated, it breaks links to page sections, probably because the height of the font is different from what the system expects. It is difficult to read from screen, while it looks clear on paper, so it may be worth setting it as default for print mode. As Mohamed Ahmed mentioned above, it makes problems displaying bold and slanted style. In addition, it only contains (extended) Arabic and Latin characters, so if a page contains Greek or Cyrillic, for example, the text looks unbalanced.

On the other hand, I am not aware of any display problems with system font settings. I believe, in Windows the system font is Arial, in Ubuntu probably Liberation Sans or DejaVu Sans, all these are Unicode fonts, where Latin, Greek and Cyrillic look fine, and links to page sections work well.

I would suggest that 'system font' made the default one. It would also be useful to add other optional fonts, such as Iranian Sans and Droid Arabic Naskh: both are open-source (as far as I know), and the latter was specifically designed for on-screen display.