Kubuntu
Used by 2 peoplekubuntu.org ↗
“It runs Kubuntu with beta updates because I like testing software on my production machine (don't do this, lol).”
Jacky Alcine Interview, Software developer (Glitch) · via Uses This 
“The X200 is my primary computer, which is a dual-boot of Kubuntu and Windows, though I haven't used Windows recently.”
Yusuke Endoh Interview, Quine fan and software developer (Ruby) · via Uses This