There seem to be a couple of free versions, a 64-bit and a 32-bit version, with the latter being less restricted than the former.[1]

I was curious about it, but they really don't make it easy to get started. There are no links to any documentation anywhere on their site. The download is hidden behind a licensing agreement and a form asking for the user's personal information. They mention GitHub (in the context of "community support") on their download page, but there are no links to any GitHub repos.

[1] - https://kx.com/connect-with-us/download/