I use FF and Chrome and avoid IE like the plague myself. But Im aware of some places that insist on IE and prevent other browsers (I think its a shortsighted and flawed policy, but... ). So I wanted to at least make the theme usable with some fallbacks for older versions - It won't have all the look and feel and wont be responsive on those older browsers, but it should at least be usable (with a big notice at the top telling people to use a decent browser ;) )
Firefox is usually my 'goto' browser, especially on XP - although my access to XP machines is now close to zero!- but I think Chrome is actually even faster - recalling the graphic Julian (I think) posted recently too ;) https://moodle.org/mod/forum/discuss.php?d=231970#p1065436
And I can do it with browser sniffing but I keep reading that this is not best practice, so I was trying to improve the theme and to get it to work with modernizr to reduce the code. Im happy enough building the fallbacks and giving older browser users a usable page (not finished in the version thats on github right now, but happy that I can do it as I progress over the break) - but wanted to get that modernizr script working if I can, as well as improve my understanding of how it works.
Its been fun learning about the flexbox layouts - frustrating at times, partly because its still in RC and browser support isn't 100% even now with the latest browsers - but fun