Not to my knowledge. There are a fair number of documents[1] describing the language to be sure, but it is difficult to divorce K from its implementation(s), so k2, k3, k4, k5 (etc) are all different languages. Your best bet is to download some implementations and try it out. k4 is built-in to kx's q which has a free download[3], just enter a line with a backslash on it to get into k.

Views are just a convenient syntax for memoization. Old versions of the value aren't available.

[1]: http://web.archive.org/web/20041022042401/http://www.kx.com/...

[2]: https://web.archive.org/web/20130801233812/http://www.kuro5h...

[3]: https://kx.com/