Chapter 13 Review Question 6

6. What programming language is Cassandra written in and why does it matter?

The primary reason is that it is the most transportable of the current languages so that the software can be ported to many different systems. But, Java does not produce the fastest executing code. (But it is not too bad for most things.) In terms of installation, it means that Cassandra can only be installed after the proper version of Java is installed.
On a side note, the CQL interactive query processor is written in Python, which is (a) even slower, and (b) needs to be installed on some systems—particularly Windows.