What’s the difference between “to VERB” and “to be VERBed”?

What is the difference between these two statements:

1. A new version of Java is ready to install.

2. A new version of Java is ready to be installed.

In this particular case, there's no practical difference. Either the subject (the Java setup tool) and object (the Java runtime) of the verb install could be called "a new version of Java", so either is fine.

Here's another example where it makes more difference:

• The man is ready to climb.
• The man is ready to be climbed.

In the first sentence, the man is has prepared himself to climb something (a wall perhaps, or maybe a tree). In the second sentence, the man is prepared for something (perhaps a small child) to climb onto him.

There's a third, more ambiguous statement which could cover both possibilities:

• The man is ready for climbing.
• A new version of Java is ready for installation.