TL;DR: 10% off Building Solid Systems in F# until 7th November 2017

Lots of people these days seem to like giving Halloween sales, but historically and theologically, Halloween is really just the precursor to the real celebration: All Saints' Day.

So in the interest of getting the details right, we're having an All Saints' Day sale, starting today for 7 days. It's already live, get your 10% off your tickets now.