Ugly LibreOffice font
Solution 1:
I answer this old thread because I experienced the same problem and I just solved it with a different method. I run Ubuntu 16.04 and LibreOffice 5.1.4.2.
Essentially, I took the answer proposed by Fitoschido in this thread: https://ask.libreoffice.org/en/question/7127/calibri-font-not-rendering-correctly/
In short, one has to edit (or create) ~/.config/fontconfig/fonts.conf and add the following block:
<match target="font" >
<edit name="embeddedbitmap" mode="assign">
<bool>false</bool>
</edit>
</match>
This has the effect of bypassing the bitmaps of the characters embedded in MS fonts and getting Ubuntu/Linux to apply anti-aliasing as I should. Now, MS fonts look much, much better in LibreOffice.
Solution 2:
This worked for me on Ubuntu 16.04 with KDE
Open KDE System Settings > Fonts > set Use anti-aliasing: field into Enabled > click Configure > dialog Configure Anti-Alias appears > set Sub-pixel rendering type: field into RGB > set Hinting style: field into Slight > press OK > press Apply > restart your programs (LibreOffice etc.).
Credit goes to http://www.ubuntubuzz.com/2016/03/how-to-fix-ugly-libreoffice-font-rendering-kde.html