Comment by andylynch

It’s proprietary but free for personal use and worth trying out (the download is absurdly small!)

Download + licenses are at https://kx.com/developers/download-licenses/

The Q for Mortals book (free online) is a good place to start, as is https://code.kx.com/q/learn/tour/

The licenses aren’t cheap but are worth it for the right problems. Definitely worth adding that the relatively few people skilled in k/q are very much in demand and paid accordingly.