[TNorthover]

I was working there at the time and even internally Jazelle documentation was hidden. Very odd for what it is.

[miohtama]

Likely licensing issue with Sun/Oracle?

[lxgr]

One rationale I've seen somewhere is that they were intentionally trying to not commit to a stable instruction set they'd need to support going forward, i.e. intentionally make support very closely coupled to a specific JVM and OS implementation.

Of course it might just also have been a cooperation with a specific JVM vendor (that could then promote their JVM as the fastest on a given set of CPUs).