100% Pure Java?

Just to be sure, does jnode only run 100% pure java apps? If so, is that something we want to actively promote?

Being able to run only 100%

Being able to run only 100% pure Java apps is much more a disadvantage than an advantage for JNode. Actually it might be good in the future to try to run native binary code too but in a safe manner which cannot break the rest of the system. Virtual machine technology, binary translation (JPC, nested vm etc.) come to mind.
On the other hand the fact that JNode itself is based on Java technology and managed code to a really large extent is worthy to be promoted.

For non-java apps see nested

For non-java apps see nested vm. If you mean java apps with native parts.. i think they will not work.